Volume 1 – Symposium: Tuesday, March 8

Group A: Digital Hydraulics Group B: Intelligent Control Group C: Valves Group D | G | K: Fundamentals Group E | H | L: Mobile Hydraulics Group F | I: Pumps Group M: Hydraulic Components:Group A: Digital Hydraulics Group B: Intelligent Control Group C: Valves Group D | G | K: Fundamentals Group E | H | L: Mobile Hydraulics Group F | I: Pumps Group M: Hydraulic Component

Volume 1 – Symposium

We are pleased to present the conference proceedings for the 12th edition of the International Fluid Power Conference (IFK). The IFK is one of the world’s most significant scientific conferences on fluid power control technology and systems. It offers a common platform for the presentation and discussion of trends and innovations to manufacturers, users and scientists. The Chair of Fluid-Mechatronic Systems at the TU Dresden is organizing and hosting the IFK for the sixth time. Supporting hosts are the Fluid Power Association of the German Engineering Federation (VDMA), Dresdner Verein zur Förderung der Fluidtechnik e. V. (DVF) and GWT-TUD GmbH. The organization and the conference location alternates every two years between the Chair of Fluid-Mechatronic Systems in Dresden and the Institute for Fluid Power Drives and Systems in Aachen. The symposium on the first day is dedicated to presentations focused on methodology and fundamental research. The two following conference days offer a wide variety of application and technology orientated papers about the latest state of the art in fluid power. It is this combination that makes the IFK a unique and excellent forum for the exchange of academic research and industrial application experience. A simultaneously ongoing exhibition offers the possibility to get product information and to have individual talks with manufacturers. The theme of the 12th IFK is “Fluid Power – Future Technology”, covering topics that enable the development of 5G-ready, cost-efficient and demand-driven structures, as well as individual decentralized drives. Another topic is the real-time data exchange that allows the application of numerous predictive maintenance strategies, which will significantly increase the availability of fluid power systems and their elements and ensure their improved lifetime performance. We create an atmosphere for casual exchange by offering a vast frame and cultural program. This includes a get-together, a conference banquet, laboratory festivities and some physical activities such as jogging in Dresden’s old town.:Group A: Materials Group B: System design & integration Group C: Novel system solutions Group D: Additive manufacturing Group E: Components Group F: Intelligent control Group G: Fluids Group H | K: Pumps Group I | L: Mobile applications Group J: Fundamental

Volume 2 – Conference: Wednesday, March 9

10. Internationales Fluidtechnisches Kolloquium:Group 1 | 2: Novel System Structures Group 3 | 5: Pumps Group 4: Thermal Behaviour Group 6: Industrial Hydraulic

Cylinder Block / Valve Plate Interface Performance Investigation Through The Introduction Of Micro-Surface Shaping

Swash plate type axial piston machines are widely used positive displacement machines in different fields of industry ranging from aerospace, agriculture, automotive, heavy machinery, etc. Lubricating gaps are the main source of energy dissipation in axial piston machines. This type of machines have three lubricating interfaces: slipper/swash plate interface, piston cylinder and the cylinder block/valve plate interface. The cylinder block/valve plate interface being one of the most critical design elements of the machine. Extensive research has been done at Maha Fluid Power Research Center in Purdue University both to model this interface and to study the effects of micro-surface shaping on the solids interacting in this interface. The aim of this work was a more in-depth simulation-based investigation into optimizing the cylinder block/valve plate interface by introducing micro-surface shaping in order to achieve a fluid film thickness that compromises between leakage and viscous friction, maximizing the overall machine performance

A Computation Fluid Dynamics Methodology for the Analysis of the Slipper-Swash Plate Dynamic Interaction in Axial Piston Pumps

This paper proposes a CFD methodology for the simulation of the slipper's dynamics of a swash-plate axial piston unit under actual operating conditions. The study considers a typical slipper design, including a vented groove at the swash-plate interface. The dynamic fluid-body interaction (DFBI) model is exploited to find the instantaneous position of the slipper, while the morphing approach is adopted to cope with the corresponding mesh distortion. A modular approach is adopted to ensure high-quality mesh on the entire slipper surface and sliding interfaces provide the fluid dynamic connection between neighboring regions. The external forces acting on the slipper are included by means of user-defined lookup tables with the simulation estimating the lift force induced by fluid compression. Moreover, the force produced by the metal-to-metal contact between the slipper and the swash plate is modeled through a specific tool of the software. The pressure signal over an entire revolution of the pump is taken as an input of the simulation and a variable time step is used to manage the high-pressure gradients occurring in the regions of inner and outer dead points of the piston. The weakly compressible characteristic of the fluid is considered by a specific pressure-dependent density approach, and the two-equation eddy-viscosity k-omega SST (shear stress transport) model is used to assess the turbulent behavior of the flow. Furthermore, the transitional model predicts the onset of transition, thus solving different equations depending on whether the flow enters a laminar or turbulent regime. In conclusion, the proposed methodology investigates the motion of the slipper in response to several external forces acting on the component. The numerical results are discussed in terms of variable clearance height, pressure distribution within the gap, and lift forces acting on the slipper under specific pump operations

Development and Application of Co-simulation and "Control- oriented" Modeling in the Improvement of Performance and Energy Saving of Mobile Machinery☆

Abstract Due to rising energy costs and tighter emissions restrictions from law regulations, mobile machinery and off-road vehicles manufacturers are forced to develop and exploit new techniques for the reduction of fuel consumption and pollutant emission. The main focus in this direction is the optimization of the matching between the fluid power circuit and the thermal engine to improve the efficiency of the hydraulic system and reducing the fuel consumption. A specific research activity has been started in this field by the authors to define methods and techniques for the mathematical simulation of off-road vehicles, where usually hydraulic systems are powered by internal combustion engines. The models proposed in the paper and the related results clearly show how these simulation tools can be used to improve the energy efficiency of the overall system, leading to an interesting reduction in fuel consumption by merely changing the engine rotational speed instead of adopting a constant-speed strategy

Performance Analysis of the Swashplate Axial Piston Pump with Hydraulic Fluid Temperatures

TVariable displacement axial piston pump can be used in a hydraulic system as the primary source of fluid power, which is suitable for high pressure and high efficiency. The power can be transfer in a hydraulic system with the help of the fluid medium. The oil leakage problem in various parts of the pump, especially the internal leakages in the piston-cylinder, swash plate-slipper pad and valve plate-cylinder block, seriously affect the performance of the pump. Therefore, it is important to know the properties of the fluid and its effect on the system performance. To study the performance of an axial piston pump, a non-linear mathematical model has been developed. The developed model has been validated with the existing results. The validated pump model has been used for performance analysis of the system. Moreover, the influence of hydraulic mineral oil at different temperatures on the piston chamber pressure, output power, and leakage flow in piston-cylinder has been explored. The present investigation has been performed in MATLAB Simulink 14a environment. The simulation result shows that the pump operating temperature range can be set as 30℃ to 60℃ for moderate ripple and output chamber pressure

Performance Analysis of the Swashplate Axial Piston Pump with Hydraulic Fluid Temperatures

943-948Variable displacement axial piston pump can be used in a hydraulic system as the primary source of fluid power, which is suitable for high pressure and high efficiency. The power can be transfer in a hydraulic system with the help of the fluid medium. The oil leakage problem in various parts of the pump, especially the internal leakages in the piston-cylinder, swash plate-slipper pad and valve plate-cylinder block, seriously affect the performance of the pump. Therefore, it is important to know the properties of the fluid and its effect on the system performance. To study the performance of an axial piston pump, a non-linear mathematical model has been developed. The developed model has been validated with the existing results. The validated pump model has been used for performance analysis of the system. Moreover, the influence of hydraulic mineral oil at different temperatures on the piston chamber pressure, output power, and leakage flow in piston-cylinder has been explored. The present investigation has been performed in MATLAB Simulink 14a environment. The simulation result shows that the pump operating temperature range can be set as 30℃ to 60℃ for moderate ripple and output chamber pressure

A Novel Fluid Structure Interaction and Thermal Model to Predict the Cylinder Block / Valve Plate Interface Performance in Swash Plate Type Axial Piston Machines

The cylinder block / valve plate interface represents one of the most critical design element in the rotating kit of axial piston machines. The thin film of lubricant between cylinder block and valve plate has to fulfill simultaneously a bearing and a sealing function under dynamic load conditions; on the other hand, it represents an important source of power losses due to viscous friction and leakage flow. An accurate prediction of the time changing characteristics of the interface, in terms of fluid film thickness, dynamic pressure field, load carrying ability and energy dissipation is necessary to generate more efficient and reliable designs. However, the complexity of the physical phenomena involved in the interface\u27s operation made the trial end error practice the main design methodology in the last fifty years. The aim of this work is to deepen the understanding of the main physical phenomena affecting the cylinder block / valve plate interface performance. For this purpose, a unique fully coupled multi-body dynamics model has been proposed to capture the complex fluid-structure interaction phenomena affecting the non-isothermal fluid film conditions. The model is able of determining the fluid film thickness as a function of the interface\u27s load condition, accounting for the squeeze film effect due to the cylinder block\u27s micro-motion and the change in fluid film thickness due to the elastic deformations of the solid parts, caused by the fluid film pressure and by the thermal strains. In addition, the impact of micro-surface shaping introduced by design or resulting from wear process can be investigated and combined with the modification of the clearance due to the normal machine operation. The model was validated by comparing the predicted surface temperature of the valve plate with measurements for two different machines, a 100 cc and a 130 cc units of commercial production. In the first case the measurements were available in literature, in the second case an specific test stands was developed as part of the experimental study of the present work. The model has also been applied to the study of the impact of micro surface shaping on the performance of the cylinder block / valve plate interface