Veranstaltung "Simulation fluidtechnischer Systeme"

Florian Schoemacker, March 7th 2018

Im kommenden Sommersemester findet wieder die Vorlesung „Simulation fluidtechnischer Systeme“ mit Hr. Prof. Christian Stammen statt. Die Veranstaltung richtet sich an Studierende, die sich für Systemsimulation interessieren. Im Rahmen der Veranstaltung werden die Grundlagen für die Berechnung hydraulischer Systeme gezeigt und in den Übungen bieten wir die Möglichkeit die Anwendung der Software DSHplus kennen zu lernen.

Die Veranstaltung wird dieses Jahr als Blockseminar im Monat September angeboten. Am 13.04. um 14 Uhr findet eine Infoveranstaltung im Seminarraum des KEmikro statt.

Aus organisatorischen Gründen sind die Teilnehmerplätze begrenzt. Eine Anmeldung zur Vorlesung in CampusOffice ist bis zum 20. April erforderlich (wird noch freigeschaltet).

Weitere Informationen findet sich im Flyer (siehe Bilder).

F. Schoemacker, M.Sc.
Tel.: +49-241-80-47748

Influence of anisotropic surface roughness on lubricated rubber friction: Extended theory and an application to hydraulic seals

March 6th 2018

Link to publication

Machine elements and mechanical components have often surfaces with anisotropic roughness, which may result from the machining processes, e.g. grinding, or from wear. Hence, it is important to understand how surface roughness anisotropy affects the contact mechanics properties, such as friction and the interface separation, which is important for lubricated contacts. Here we extend a multiscale mean-field model to the lubricated contact between a soft (e.g. rubber) elastic solid and a rigid countersurface. We consider surfaces with anisotropic surface roughness, and discuss how the fluid flow factors and friction factors depend on the roughness power spectral density, as well as on the location of roughness on the interacting solids. Finally, we present an experimental study of the lubricated sliding contact between a nitrile butadiene rubber O-ring and steel surfaces with different kinds of isotropic and anisotropic surface roughness. The good quantitative comparison between the experimental results and the theory predictions suggests that the multiscale lubrication mechanisms are accurately captured by the theory.

J. Angerhausen, M.Sc., M.Sc.
Tel.: +49-241-80-47732

Fire Update – expected dates

December 21st 2017

The work on the recommissioning of the laboratory I is making progress. After several call for bids, e.g., for the electrical infrastructure, have been published, the work on the concrete structure and the preparation for the power rail installation has begun. The rail should be installed and connected in the beginning of 2018.

Meanwhile, the replacement area in the Karl-Friedrich-Street (KFS) is used to full capacity, so that the experimental research capabilities are reinstated on a broader scope. Only the fields of acoustic and climatic measurements are currently still limited due to the unavailable / missing infrastructure, as well as the operation of test rigs with high power demands. In the KFS laboratory several test rigs with a power scope of 50 kW are operated. Additionally some laboratory space is obtained from the Aachen Center for Integrative Lightweight Production (AZL), which we would like thank cordially!

All in all the Bau- und Liegenschaftsbetrieb NRW (BLB) estimates to hand over the fully reinstated laboratory in the 4th quarter of 2018. Unfortunately, an exact schedule is not at our disposal at the moment. This date includes the termination of all work as well as the new acoustic chamber and the new climate chamber. Prior to this a stepwise recommissioning of certain test rigs will begin in February, so that the laboratory I, if only partially, will be accessible for visitors and guests during the upcoming IFK.

Dr.-Ing. C. Schleihs
Tel.: +49-241-80-47702

Influence of a new hollow piston design on volumetric losses of a common-rail pump

December 7th 2017

A paper on “Influence of a new hollow piston design on volumetric losses of a common-rail pump” was published at the ASME/Bath Symposium on Fluid Power and Motion Control 2017 in Sarasota.

Within the cluster of excellence "Tailor-Made Fuels from Biomass" alternative fuel candidates are being investigated. One of the most promising candidates is Di-n-Butylether (DnBE). Because of its lower viscosity compared to diesel, the injection pump expiriences high volumetric losses. A new hollow piston concept was developed to reduce aforementioned losses. Test rig measurements show good results and a great potential for hollow pistons.

M. Rückert, M.Sc., M.Sc.
Tel.: +49-241-80-47721

Holistic Investigation of a 50/50 DnBE - 1-Octanol blend regarding the complete injection system

December 7th 2017

A paper on “Holistic Investigation of a 50/50 DnBE - 1-Octanol blend regarding the complete injection system” was published at the seventh international Tailor-Made Fuels conference in Aachen.

In this publication the focus is put on the biofuel candidates Di-n-Butylether (DnBE) and 1-Octanol (1-OCT). With the good spray-characteristics of DnBE and the good tribological and rheological properties of 1-OCT, blending these two fuels could increase the overall efficiency of the engine and injection system. A blend containing 50 vol. % DnBE and 50 vol. % 1-OCT is investigated. The work focuses on key elements of the engine and injection system. Starting with pump measurements and lubricity evaluation using the High-Frequency-Reciprocating-Rig (HFRR). In terms of ignit-ability, the derived cetane number (DCN) of the blend is determined using the Advanced Fuel Ignition Delay Analyzer (AFIDA). Furthermore, experiments using a single cylinder engine are conducted. The results and possible blending strategies are discussed by comparison the blend with the pure fluids.

Sources: left VKA, right IFAS

M. Rückert, M.Sc., M.Sc.
Tel.: +49-241-80-47721

Hollow Pistons in Hydraulics – Possibilities of Increasing Volumetric Efficiencies

December 7th 2017

A paper on "Hollow Pistons in Hydraulics – Possibilities of Increasing Volumetric Efficiencies" was published at the 23rd international fluid power conference Hervex in Romania.

Within the cluster of excellence "Tailor-Made Fuels from Biomass" a new hollow piston concept for injection pumps was developed and succesfully tested. In hydraulics, high leakage within pumps appear due to low viscosities for example. A low viscosity application is water hydraulics. Therefore, the hollow piston concept was adapted to water hydralics and first simulative studies were conducted. The simulations indicate a potential of the same magnitude as in injection pumps.

M. Rückert, M.Sc., M.Sc.
Tel.: +49-241-80-47721

Analytical, Experimental and Numerical Methods to Quantify the Pressurization in the Piston Chamber of Axial Piston Machines

November 16th 2017

A paper on “Analytical, Experimental and Numerical Methods to Quantify the Pressurization in the Piston Chamber of Axial Piston Machines” was published at the 10th JFPS International Symposium on Fluid Power in Fukuoka.

The behavior of the tribological system piston - bushing in axial piston machines is investigated experimentally on a single piston test rig at the IFAS laboratory. Due to extensive test bench peripherals, various operating states can be reliably reproduced and component design variants examined. By means of a synchronously driven rotary valve, a realistic commutation between high and low pressure level takes place.
In addition to the hydraulic-mechanical losses, due to the axial and tangential friction force, as well as the loss due to leakage at the sealing gap and the dissipated compression work is mentioned. Depending on the design of the commutation, this loss leads to a reduction in the volumetric or hydraulic-mechanical efficiency. Main influencing factors are the high and low pressure levels, as well as the dead volume of the displacement unit and the bulk modulus of the hydraulic fluid, which is lowered by entrained gas. Avoiding the dissipated compression work is not possible even when the dead volume is reduced to zero.

Dipl.-Ing. M. Gärtner
Tel.: +49-241-80-47739

Control Concept for a Novel Integrated Pressure Booster

November 15th 2017

A paper on the "Control Concept for a Novel Integrated Pressure Booster” was published at the 23rd Hervex Conference in Baile Govora, Romania.


The paper proposes a novel concept for pressure boosters based on rotational equipment. Instead
of double piston boosters as they are common in industrial applications today, the proposed concept is
based on a pneumatic radial piston motor. During one cycle, all cylinder chambers act as actuator and
compressor as well. The paper shows a mathematical model of the cycle and its simulative implementation.
A control concept using fast switching valves is proposed. To evaluate the efficiency, a parameter variation is
undertaken. This includes the number and size of the pistons as well as pressure levels for input and output
respectively. The thermodynamic concept of exergy is used to compare the different system configurations.

Mathematical Modeling of a Pneumatic Vane Motor in Matlab/Simulink

Stephan Merkelbach, November 14th 2017

A paper on “Mathematical Modeling of a Pneumatic Vane Motor in Matlab/Simulink” was published at the 10th JFPS International Symposium on Fluid Power in Fukuoka.
Air driven motors are used in a variety of applications, for example as drives for tools in manufacturing. Pneumatic vane motors in particular feature high speed and eminent power density. The paper presents the development and experimental validation of a one dimensional simulation model for pneumatic vane motors in Matlab/Simulink. The model developed in the study can be used as a basis for future work on the optimization and control of pneumatic vane motors. The validation is carried out by an experimental setup which consists of the vane motor mounted on a common shaft with a hydraulic gear pump building up the load.


November 13th 2017

A paper on “Validation of an Enhanced Model of Steady-State Flow Forces for Spool Valves” was published at the 10th JFPS International Symposium on Fluid Power in Fukuoka.


One of the valve types often used in hydraulics is the spool-type valve. A typical example of a spool valve is a directional valve. In order to move the spool, an actuator is needed to overcome forces acting on the spool. Beside spring and friction forces, flow forces are the most relevant. They influence the static and dynamic performance of valves.
In this paper, the validation of an enhanced model for the calculation of steady-state flow forces in spool valves is described. Both the momentum influx and the efflux are considered in the model. In addition, it was found that the accuracy of the calculation of steady-state flow forces can be improved by using variable quantities, such as the inlet and outlet flow angles and the discharge coefficient, instead of constants.

P. Bordovsky, Ing
Tel.: +49-241-80-47742

Analysis of Flow Angles and Flow Velocities in Spool Valves for the Calculation of Steady-State Flow Forces

November 13th 2017

A paper on “Analysis of Flow Angles and Flow Velocities in Spool Valves for the Calculation of Steady-State Flow Forces” was published at the 15th Scandinavian International Conference on Fluid Power in Linköping.


A detailed analysis of the flow inside valves has become necessary for the optimization of their static and dynamic performance. In addition, the flow velocities and flow angles on defined areas inside valves are needed for the estimation of physical quantities such as flow rates, flow forces, etc.
Within this paper, measurements and CFD-simulations of a 2/2-way spool type test valve are analyzed regarding flow angles and flow velocities including their distribution on the inlet and outlet areas. Different spool edge geometries are investigated in both flow directions. Furthermore, the impact of a chamfer and a fillet on a spool edge, on the flow angles and the flow velocities are analyzed.
The analysis results show that the shape of a spool edge influences the flow angles and the flow velocities. Both flow variables are significantly affected by the direction of the fluid flow through the valve. Moreover, considering the same inlet area, an increasing chamfer width, respectively an increasing fillet radius, result both in lower inlet and outlet flow angles.

P. Bordovsky, Ing
Tel.: +49-241-80-47742

Interaction between Swash Plate Movement and Commutation in Axial Piston Machines

Florian Schoemacker, November 13th 2017

A paper on “Interaction between Swash Plate Movement and Commutation in Axial Piston Machines” was published at the 10th JFPS International Symposium on Fluid Power in Fukuoka.


In an axial piston pump the alternating pressure force of the pistons produce a periodically changing torque load on the swash plate. The torque load results in a movement of the swash plate, especially if the damping of the swash plate is quite low. The swash plate movement changes the piston stroke and therefore interacts with the commutation which leads to altered piston pressure forces.

The impact of different valve plate designs, using silencing grooves and bores, on the swash plate torque load and the resulting oscillation has been investigated via simulation. The results show that the design of the valve plate has a major impact on the periodic behavior of the torque load. Therefore this aspect needs to be considered while designing pumps for closed-loop control.

F. Schoemacker, M.Sc.
Tel.: +49-241-80-47748

Disc Brake with Hydromechanically Controlled Brake Torque for Railway Applications

Matthias Petry, November 10th 2017

A paper on “Disc Brake with Hydromechanically Controlled Brake Torque for Railway Applications” was published at the 10th JFPS International Symposium on Fluid Power in Fukuoka.


Hydraulic disc brake systems are widely spread in commuter train applications. Due to their operation with an open loop control system, they are not able to deal with the influences of varying conditions surrounding the frictional contact zone between the brake pads and the disc. This results in a variable friction coefficient and affects the system performance. To detect the variation a closed loop control system with a feedback signal needs to be implemented in existing brake solutions to maintain high reliability and operating permit. This paper examines the design features of an existing system and finds a suitable mechanical feedback signal, whose eligibility is experimentally verified. Subsequently the geometrical calculations of the system are made and the control system is simulated. Based on the simulation results a preliminary design of the system is presented.

Dipl.-Ing. M. Petry (geb. Hirtz)
Tel.: +49-241-80-47733

The Influence of Temperature and Surface Structure on the Friction of Dynamic Hydraulic Seals

November 10th 2017

A paper on “The Influence of Temperature and Surface Structure on the Friction of Dynamic Hydraulic Seals” was published at the 10th JFPS International Symposium on Fluid Power in Fukuoka.


A test rig and a transient, finite element (FE) based elastohydrodynamic (EHD) simulation for translational hydraulic seals have been set up to investigate a soft, lubricated line contact in detail. In this paper the influences of temperature and surface structure on the friction force is investigated numerically and experimentally. The focus is upon the mixed friction regime as - especially during a change in the cylinder stroke’s direction - solid body friction and fluid friction occur in the tribological contact between seal and cylinder surface.

J. Angerhausen, M.Sc., M.Sc.
Tel.: +49-241-80-47732

New Appointment of the IFAS Professorate

August 10th 2017

Dr. Katharina Schmitz, currently technical director at Hunger Maschinen GmbH, was appointed the university professorate for Fluid Power Drives and Systems by the RWTH Aachen University starting from March 1st, 2018.

She will take over the management of the institute from Prof. Murrenhoff commencing with the 11. International Fluid Power Conference IFK (19.-21.03.2018 in Aachen).

The new appointment ensures long-term research and teaching in the field of fluid power at RWTH Aachen University. Therefore the institute will be renamed in to Institute for Fluid Power Drives and Systems.

Elastohydrodynamics for Soft Solids with Surface Roughness: Transient Effects

Julian Angerhausen, June 12th 2017

Link to publication

A huge number of technological and biological systems involve the lubricated contact between rough surfaces of soft solids in relative accelerated motion. Examples include dynamical rubber seals and the human joints. In this study, we consider an elastic cylinder with random surface roughness in accelerated sliding motion on a rigid, perfectly flat (no roughness) substrate in a fluid. We calculate the surface deformations, interface separation and the contributions to the friction force and the normal force from the area of real contact and from the fluid. The driving velocity profile as a function of time is assumed to be either a sine function, or a linear multi-ramp function. We show how the squeeze-in and squeeze-out processes, occurring in accelerated sliding, quantitatively affect the Stribeck curve with respect to the steady sliding. Finally, the theory results are compared to experimental data.

J. Angerhausen, M.Sc., M.Sc.
Tel.: +49-241-80-47732

New project: Rail vehicle brake with hydraulic-mechanically controlled braking torque

Christian Schleihs, May 30th 2017

DFG-knowledge transfer project (MU 1225/40-1)
07/2017 - 06/2019
The objective of the knowledge transfer project is the investigation of a practical and simplified system for the implementation of the direct frictional force control based on the self-energizing hydraulic brake (SEHB) developed at IFAS. The main focus is on the development of a prototype based on components of today's braking systems with the aim of a simple integration into an established rail vehicle in the local traffic area as well as its testing and validation in the application. As industrial partner, Hanning & Kahl GmbH & Co. KG, Oerlinghausen, accompanies and supports the project funded by the DFG.

Dipl.-Ing. M. Petry (geb. Hirtz)
Tel.: +49-241-80-47733

IFAS Pentecost Excursion 2017

Florian Schoemacker, May 9th 2017

This year IFAS offers an excursion to company of the fluid power industry. The excursion is dated within the pentecost week, from 06.06. to 09.06.

Please send your registration to:

Further information can be found on the information sheet.

F. Schoemacker, M.Sc.
Tel.: +49-241-80-47748

11th IFK 2018 - CfP now open

March 10th 2017

The 11th edition of the International Fluid Power Kolloquium in Aachen will be held from March 19 through 21, 2018.
The "Call for Papers" is now open.
For further information and downloads of CfP and an abstract template, please visit

IFAS receives VIP/VIP+ validation award for STEAM project

Roland Leifeld, February 13th 2017

For the research results in the project STEAM the Institute for Fluid Power Drives and Controls (RWTH Aachen) was awarded second place in the VIP/VIP+ validation prize by the German Federal Ministry for Education and Research (BMBF).
It was presented by Parliamentary State Secretary Stefan Müller on February 1st, 2017, within the Innovation Convention “Validation of the Social and Technological Potential of Scientific Research" (VIP/VIP+).

For further information about the STEAM project, see:

R. Leifeld, M.Sc.
Tel.: +49-241-80-47734

New project: Development of a standardized, simplified process control and test evaluation beyond the current stability limit of gas-based deep drawing tests to determine warm extrusion material data

February 2nd 2017

AiF/FOSTA (IGF-Nr. 19229 N/2)
12/2016 - 11/2018

In collaboration with the IBF (Institut für Bildsame Formgebung) a new deep-drawing test for the determination of material data is currently being developed. In this process, a glowing sheet metal sample is subject to a one-sided pressure load and hereby reshaped. The aim of this project is to improve the stability of the forming process, for which proportional high-pressure pneumatics as well as new control methods are to be tested.

G. Matthiesen, M.Sc., M.Sc.
Tel.: +49-241-80-47730

New project: Survey on the Industrial Internet in the sector of fluid power – shown by the example of an automated commissioning process

February 2nd 2017

FKM - Forschungsfonds Fluidtechnik (FKM-Nr. 704080)
02/2017 - 01/2018

The case study examines different aspects of the Industrial Internet by investigating the special case of an automated commissioning process of a machine. The goal is to propose a need of action for the sector of fluid power and all related parties in order to take part at its benefits and stay involved in a highly advanced future, achieved by the 4th Industrial Revolution.

R. Alt, M.Sc.
Tel.: +49-241-80-47729

New project: Decentralized compact hydraulic power supply

January 31st 2017

AiF/FVB (IGF-Nr. 19224 N/2)
01/2017 - 03/2019

During the project the IFAS and the Institute for Machine Elements and Machine Design (IME) will develop a functional model for an electro-hydraulic axis. For this purpose a high-speed pump and an associated transmission will developed, which is driven by a high-speed electric motor. The aim is to increase the power density of the power unit by increasing the rotational speed level which make it attractive for mobile applications.

T. Pietrzyk, M.Sc.
Tel.: +49-241-80-47746

New project: Development of a bio-polymer based hydraulic fluid with plant-based corrosion protection additives (BioHydra)

January 31st 2017

BMEL - Fachagentur Nachwachsende Rohstoffe e. V. (FKZ: 22013716)
12/2016 - 05/2019

At the moment a completely new hydraulic fluid with a water content of more than 90 % will be developed at IFAS. Further fluid components will be primary based on renewable resources. To achieve the needed viscosity and lubricity bio-polymers based on carbohydrates will be used. Due to the high water content corrosion protection is paramount during the entire project. Thus, for the first time secondary plant metabolites will be used as anticorrosive additives.

N. Otto, M.Sc.
Tel.: +49-241-80-47731

ISC 2016: Influence of additives on rod seals

November 23th 2016

A paper on “Influence of additives on the frictional behavior of hydraulic rod seals” was published at the International Sealing Conference (ISC 2016) in Stuttgart. The Authors are Felix Fischer, M.Sc., Prof. H. Murrenhoff and Dr. O. Reinertz.


Due to the high power density, high efficiency and the robust design, hydraulic cylinders are widely used in technical applications. Energy losses within the hydraulic cylinder as well as dynamic losses arise primarily in the hard-soft contacts of the seals. Specifically dynamic effects, such as the stick-slip phenomenon, difficult positioning tasks with high accuracy requirements and are strongly correlated to the frictional behavior of the tribological system (TS). Methods to reduce, or even to eliminate these phenomena require further investigations to obtain a better understanding of the TS “seal-rod”.

Initial experimental studies of the authors have shown that the additive package of the oil has a major impact on the friction characteristics of the rod seal, whereas the influence of the viscosity is of secondary importance. When using automatic transmission fluid as working fluid, the dynamic behavior of the system should be considered more docile than in the case of conventional hydraulic oil. Here, the friction modifiers (FM) play a special role as components of the automatic trans-mission fluid´s additive package. using a friction test rig it was revealed, that the addition of a model FM helps to influence the frictional behavior of the TS positively.

In this paper, the effect of a variation of the FM molecule on the frictional behavior of the TS is investigated experimentally. In order to achieve this goal, FM are add-ed to a conventional hydraulic fluid and the impact on the TS “seal-rod” is deter-mined and discussed. For this purpose, the system is excited with an actuator and the trajectory of the frictional force is analyzed. Furthermore, quasi-stationary Stribeck curves are recorded and compared to the results from the excitation experiments, where a causal relationship can be pointed out.

F. Fischer, M.Sc.
Tel.: +49-241-80-47728

ISC 2016: Influence of anistoropic surfaces

October 20th 2016

At the International Sealing Conference (ISC 2016) in Stuttgart the paper “Influence of anisotropic surfaces on the friction behaviour in hard/soft line contacts” was published. Authors are Julian Angerhausen, M.Sc. and Prof. H. Murrenhoff


When modelling leakage rate, friction force or fluid and contact pressure distribution of hydraulic seals often a perfectly smooth or randomly rough isotropic surface is assumed. But due to different surface finishing methods, like coating, grinding or polishing, rough and anisotropic surface topographies are generated. In this paper an experimental investigation of the influence of such anisotropic surfaces on the friction behaviour of a hard-soft contact is reported.

A test rig has been designed and set up to investigate a soft, lubricated line contact in detail. An O-ring cord is brought into contact with the lateral surface of an uniform rotating hard cylinder. In order to simulate a cylinder-on-flat test configuration, the diameter of the hard cylinder is significantly larger than the O-ring’s diameter. Three cylinders with different surfaces are used: One sandblasted, isotropic surface and two anisotropic surfaces, grooved orthogonal or longitudinal to the direction of motion. The contact pressure is adjustable by varying the test weights. The test chamber is temperature-controlled to consider different viscosities of the fluid and the temperature-dependent material behaviour of the elastomer.

Friction force and rotational speed are measured to carry out Stribeck curves and compare the influence of anisotropic surfaces for different relative velocities, temperatures and contact pressures. Very slow velocities (2.5 mm/s - 25 mm/s) are studied in particular. Additionally the effect of idle time on the breakaway force is investigated. A distinct influence of anisotropic surfaces can be detected. The friction force decreases when the surface is grooved longitudinal to the direction of motion.

J. Angerhausen, M.Sc., M.Sc.
Tel.: +49-241-80-47732

Update regarding the fire damage - New reopening date of laboratory 1 and substitute lab

October 7th 2016

The reopening date of laboratory hall 1, which was first expected to be the end of 2016, has proven impossible to maintain. Due to the time intensive modernization of the electrical infrastructure, the ventilation and the fire prevention system in laboratory 1, the reopening is presumably planed for the 3rd to 4th quarter of 2017! An exact plan of the necessary renovations by the Bau- und Liegenschaftsbetrieb (BLB) NRW, which illustrates this schedule, is not yet available.
In the meantime we resort to the utilization of the laboratory space in hall 2. The research activities in hall 2 are successfully continuing, since its reopening at the beginning of May.
Additionally, a substitute space available on short notice is being acquired in cooperation with the University’s central administration in order to expand the current capacities and relieve laboratory 2, so that the research capabilities can also be expanded. With this step, the research abilities of the institute will be reinstated on a broad range. Only the fields of acoustic and climatic measurements are currently still limited due to the currently unavailable missing infrastructure, as well as the operation of test rigs with high power demands.

O+P: Compensation of Brake Force Oscillations

Matthias Petry, August 22nd 2016

The paper "Compensation of brake force oscillations with a self-energizing hydraulic brake (SEHB)" was published in the O+P Fluidtechnik Journal, edition 07/08 2016. Authors are Dipl.-Ing. Matthias Petry, Dr.-Ing. Olivier Reinertz and Prof. Dr.-Ing. H. Murrenhoff.

Friction force and brake torque oscillations of disc brake systems represent a relevant topic regarding brake comfort and safety aspects. The self-energizing hydraulic brake (SEHB) makes it possible to compensate these oscillations actively. ​Compensation rates up to 86% are possible for both constant speed and speed ramps.

Dipl.-Ing. M. Petry (geb. Hirtz)
Tel.: +49-241-80-47733

Wolfgang Backé passed away († July 21st 2016)

July 27th 2016

Shortly before entering his 88th year of life he died caused by a severe illness.

On the 21st of July 2016 fluid power lost an outstanding researcher and advocate of hydraulics and pneumatics with the death of em. Univ. Prof. Dr.-Ing. Dr. h. c. mult. Wolfgang Backé. Wholeheartedly his life belonged to the development of fluid power. The decision was made early on by him studying mechanical engineering at RWTH Aachen University choosing the study direction of production engineering. He deepened the subject in fluid power research and got promoted to Dr.-Ing. in 1959 at the machine tool laboratory WZL under the direction of Prof. Opitz. Building upon this he further qualified by a habilitation towards the subject of flow forces in valves in the year 1962.

After a time as Chief Engineer at WZL, a following industrial career as head of the development department of the company Rheinstahl Wagner and teaching obligations by his Venia Legendi for the subject “Ölhydraulische Steuerungen und Antriebe“ in Aachen, Wolfgang Backé , born on July 25th in 1929, accepted the offer to take over the newly created chair “Lehrstuhl für hydraulische und pneumatische Antriebe und Steuerungen“ (IHP) and the directorship for the Institute carrying the same name, todays IFAS. He was head of the Institute till his official retirement in 1994 and led it to the biggest and most renowned institution in the field of fluid power with national and international recognition and an outstanding worldwide reputation.

Wolfgang Backé was scientist and researcher with full believe and thereby devoted to fluid power like nobody else. With his creative power he transformed fluid power in Germany, Europe and overseas. In academia as well as in the industrial sector he helped this process by manifold consulting and his directorships in company boards leading to the success story we know. Early on he forged unique networks, which are still used by the following generations of researchers in our field. For me it is important to emphasize that these networks also stretched into the social environment and actively included the partners. This way many conference, business and cultural travels were backed by the families. They were part of it, involved in the preparation and unofficially the group was called the “Fluid Power Gang“.

He passed on his knowledge by teaching students and conducting as well as supervising research and development projects with the upcoming engineering generations. Even after being retired he still actively participated in the scientific live and kept publishing papers and books.

He supervised 124 doctoral candidates and guided them to graduation, thereby starting their subsequent industrial careers. Many former students and scientific researcher are employed in notable positions in the fluid power industry. Some returned to Universities and Universities of Applied Sciences to pass on the knowledge to young academics they themselves learned through him. Some examples are Prof. Young-Xiang Lu, who was President of the Zhejiang University in Hangzhou and Prof. Chung-O. Lee, who for a long time was Minister of Research and Technology in South Korea.

Manifold contacts and partnerships with other institutes in the field of fluid power in America, Asia, Australia and Europe give evidence of his worldwide recognition in the industry. Within RWTH Aachen University his interdisciplinary research was backed by collaborative research centers where he participated and took over leadership functions. This work was complemented by common research projects initiated and guided by the Engineering Federation Fluid Power within VDMA in Frankfurt. These projects covered fluid power in industrial and mobile hydraulic applications, handling and automation technology, as well as biomedicine. In addition to these commitments in his subject, he also participated in the academic self-administration of the University. In that regard he was Dean of the Faculty of Mechanical Engineering in 1974 and 1975. Without exaggeration it can be stated that based on his research and teaching focal points, as well as his involvement in the in appointments for Institute leaderships , his research, development and teaching activities, todays fluid power in Germany has achieved a highly recognized technical stand.

Together with high ranked industrial representatives he founded the society for the advancement of fluid power (Fördervereinigung Fluidtechnik, e.V., Aachen) to promote, e.g., infrastructural projects, conduct national and international conferences and support teaching. This way he was able to found the biannually organized international fluid power conference. It started in 1974 as 1. AFK and continues today with the IFK, alternating between the cities of Aachen and Dresden.

Next to a lot of academic honors, he was awarded three honorary doctor degrees and two honorary professorships. He obtained the highly ranked German Federal Cross of Meritin 1988 (“Verdienstkreuz am Bande des Verdienstordens der Bundesrepublik Deutschland“) and in 1997 (“Bundesverdienstkreuz 1. Klasse der Bundesrepublik Deutschland“).

With his death the Institute - and with it the “Fördervereinigung Fluidtechnik“ - loses his highly regarded scientist, researcher and teacher, as well as its founding member.

Our deep sympathy is with his wife, Ms. Rosi Seiz-Backé, and his Family. We will always keep our mentor in highest regard and in honorable memory.

Aachen, July 2016
Hubertus Murrenhoff

Update regarding the fire damage - Reopening of lab hall 2

May 9th 2016

At the beginning of this week the IFAS and its employees celebrated the reopening of the smaller lab hall 2 much sooner than expected. Hence, research activities are possible in hall 2. This also includes the opening of our library and the conference room.

Dear Friends, Sponsors and Partners of IFAS

May 2nd 2016

Please click here to get to the message from May 2nd 2016

Update regarding the fire damage - Removal of ventilation system underway / Infrastructure partly operational

April 6th 2016

One part of the ventilation system, emerging over the destroyed area of our neighboring institute WZL, has been removed. The remaining part, situated above the IFAS laboratory roof, is expected to be removed by mid-April. The necessary preliminary work is already underway.
The majority of the debris in the area surrounding the completely destroyed WZL laboratory has also been removed. Parts of the IFAS laboratory infrastructure are once again operational. Plans to restore the electrical supply and distribution are being discussed. These steps will however take some time. The recommissioning of the pneumatic pressure supply network, the water supply and radiators is nearly finished. The central cooling water supply for test rigs and hydraulic units will follow shortly.
The cleaning of the laboratory and the measuring equipment is mostly finalized. The re-installment of the measuring equipment, which was cleaned in a separate location, is underway. The largest part of the laboratory is therefore awaiting final inspection of the cleaning work. This will take place after the outstanding greater clean-up operations in the vicinity of the laboratory are completed.

Update regarding the fire damage - Cleaning efforts are in progress

March 10th 2016

Due to the fast cleaning process of the building and the inventory, IFAS hall 1 is completely decontaminated. In combination with isolation interventions in compliance with the chemist, the area is categorized as hazard class 0. The current cleaning process is focused on switchboards, test boxes and the test rigs situated within as well as rooms located within the lab. First steps regarding the restart of the infrastructure are also in progress. Since beginning of the week heavy machinery is used for the cleanup efforts of the destroyed neighbouring institute hall of the WZL.

Update regarding the fire damage - Status of the decontamination process

February 25th 2016

Parallel to the ongoing decontamination of the inventory, the "Bau- und Liegenschaftsbetrieb NRW" also assigned the decontamination of the building itself. This process has begun and is being carried out by the company BELFOR. The machine decontamination process in our main lab is almost completed. An on-site inspection by a planning office for the infrastructure's recommissioning promises a quick return to normal operation in our lab - first on a limited level, reaching full operation step by step.

Update regarding the fire damage - Approval of the structural engineers was issued

February 18th 2016

Meanwhile all effected laboratory rooms of IFAS were examined and approved for entering by the structural engineers. Exempted for now is the anechoic room which is partly located in the fire damaged area of WZL machine tool laboratory. Here we need to wait for the clearance of fire damaged parts and materials before the access becomes possible. Thanks to the approval of the structural engineers the damage to the central infrastructure can be analyzed and the necessary steps for its recovery will be taken accordingly.

Update regarding the fire damage - pictures

February 15th 2016

Cleaning work is in progress.

Update regarding the fire damage

February 11th 2016

The structural clearance of our laboratory was partly issued, so that the building can be entered. Thus, the cleaning and the chemical neutralization of the lab was started by the company BELFOR DeHaDe GmbH, which was appointed by the insurer and the RWTH University. A preliminary categorization of the main lab has been set to hazard class 1 until completion of the chemical analysis.
The attached test chambers, the labs and offices on the first floor have partially been categorized as hazard class 2 and are not yet cleared in structural regard. For the second lab building, which is less affected, the chemical analysis is still pending as well. Luckily, the basement could be kept dry during firefighting operations. The structural clearance of all other labs is pending and the stepwise reactivation of the infrastructure needs to be carried out.

Message to our friends, supporters, customers, sponsors and associations regarding the fire in the neighbouring building on February 4th, 2016

February 7th 2016

Please click here to get to the message from Feb. 7th 2016