Maha Fluid Power Research Center - Purdue University Mechanical Engineering

2025 Maha Fluid Power Conference

May 13th - 14th, 2025, Purdue University, West Lafayette, IN, United States

Event description

The 2025 Maha Conference is scheduled for May 13 (Tue) and May 14 (Wed) at Purdue University. This members-only event is open exclusively to Industry members of the Maha Fluid Power Research Center, select prospective members, and Purdue faculty and students.

The event will feature about 25 technical presentations from Maha and other affiliated research labs. The attendees will also have opportunities to network during coffee breaks, lunches and a conference dinner, all include with registration. Additionally, participants can tour the Maha Fluid Power Research Center facilities and the Purdue’s battery and engine technology labs.

Executive members of the Research Center are entitled to 3 free participant registrations, while Basic Members are provided with 1. Additional participants will require a $450 registration fee. The free registrations are determined by each industry representative (see list of the Maha Industry Board Members under "Maha Membership").

We hope to meet you in May at Purdue to keep up to date with the latest research progress in fluid power!

The schedule for the conference is given below.

Tentative Schedule

Tuesday, May 13

7:30 AM - 8:30 AM WALC 1121	Breakfast
8:30 AM - 9:00 AM WALC 1132	Welcoming Remarks and Introduction Andrea Vacca
9:00 AM - 10:20 AM WALC 1132	Session A: Pump Simulation (Chair: TBD) Ajinkya Pawar: Comparative Analysis of External Gear Machine Performance Considering Deformation and Thermal Effects Abstract: The energy efficiency of external gear pumps (EGPs) in high-pressure applications is significantly influenced by power losses in the lubricating interfaces that seal internal displacement chambers. Accurately modeling these interfaces is crucial for predictive simulations, yet literature presents varied approaches with differing assumptions. This paper addresses this challenge by utilizing Multics-HYGESim, a comprehensive simulation tool developed by the authors’ research team. The model integrates thermal-tribological effects, including meshing, lubricating films at tooth tips, journal bearings, and lateral interfaces. It accounts for realistic fluid properties, cavitation, aeration, mixed lubrication, and material deformation of gears, bushings, and housing. Recent advancements to the model introduce coupled thermal analysis, capturing heat transfer in fluid, lubricating interfaces, and solid domains to predict body temperatures and thermal deformation. These pressure and thermal deformations critically impact internal balancing and pressurization, making their realistic quantification complex. Using a commercial EGP with available experimental efficiency data, this study evaluates EGP performance in terms of housing wear, outlet pressure ripple, volumetric and hydromechanical efficiency under different modeling assumptions, ranging from rigid body motion with analytical lubrication models to fully coupled multi domain thermal analysis. The results provide a detailed breakdown of power loss and leakage sources, guiding EGP designers in assessing the impact of deformation and lubrication modeling on performance predictions. Kai Ping Qwah: A Multi-Domain Thermal Model for Simulating Performance of High-Pressure Gerotor Pumps Abstract: Gerotors are widely utilized as positive displacement units in low-to-medium pressure applications, such as automotive engine oil and fuel systems. Latest technological require higher operating pressure, and gerotor units are still a good candidate. Advanced simulation models can accelerate progresses in gerotor designs. However, designing gerotor pumps for high-pressure operation necessitates advanced modeling approaches that account for thermal effects, often overlooked in conventional isothermal models. Current methodologies, including 3D CFD, lumped parameter (LP), and coupled LP-lubricating interface models, fail to capture intricate temperature variations that influence frictional losses and leakages. To address this gap, this paper presents a multi-domain numerical model that integrates thermal effects into the simulation of gerotor pump operation. The model incorporates mass and energy conservation equations in the fluid domain using the LP methodology. Thermal Reynolds and energy equations are employed to simulate the lubricating interface, capturing thermoelastohydrodynamic (TEHL) effects, while solid components’ heat transfer and thermal deformation are evaluated establishing a comprehensive coupling with lubricating interfaces and tooth space volumes (TSVs). The proposed model provides detailed estimations of operating temperatures across pump's outlet, TSVs, lubricating interfaces, and solid components. Comparative analysis against isothermal models reveals significant differences in predicted frictional losses and leakages, emphasizing the critical role of thermal effects in gerotor pump performance. This work shows the importance of thermal considerations in design gerotors for high pressure applications advancing the state of the art in gerotor pump modeling and simulation. Harrison Han: Dynamic Simulation of Slipper Retainer Ring of an Axial Piston Pump Abstract: The retainer-ring hold-down system plays a critical role in controlling the dynamic behaviors of slippers in swashplate-type axial piston machines. It directly influences the tribological performance of the lubricating interfaces, which affects the efficiency and reliability of these machines. While numerical simulations can predict performance metrics, such as power loss and leakage, for swashplate-type axial piston machines, existing methods often oversimplify the hold-down system by neglecting the retainer ring's dynamics, leading to reduced predictive accuracy. To address this limitation, this study presents a novel approach that explicitly simulates the micro-motion of the retainer ring and its dynamic interaction with the slipper-piston assemblies with the consideration of elastohydrodynamic effects in the corresponding lubricating interfaces. The solid body and tribological behaviors predicted by the proposed model are validated against finite element method analysis as well as experimental data from a commercial water-lubricated swashplate-type axial piston pump. The results demonstrate the importance of simulating the micro-motion of the retainer-plate and dynamic coupling of the hold-down system by showcasing the proposed model's ability to accurately predict the central spring force required to achieve an improved balance between viscous power loss, solid-body contact, leakage, and cavitation damage based on the specific design priorities. Jinhwan Lee: A Elastohydrodyanmic Simulation for Radial Piston Motor and Its Experimental Validation
10:20 AM - 10:40 PM WALC 1121	Coffee Break
10:40 AM - 12:00 PM WALC 1132	Session B: System Design (Chair: TBD) Zihao Xu: Experimental Investigation for Multi-Common Pressure Rail Systems with Three Pressure Rails and Three-Chamber Cylinders Marvin Durango: Demonstration of a Digital Twin framework for a two-actuator hydraulic application Prithvi Naresh Chandiramani: A Pump Decoupled Architecture to Allow Increasing Energy Efficiency of Hydrostatic Transmission Solution based on Fixed Displacement Secondary Units Abstract: Despite being inherently throttle less system, Hydrostatic Transmission (HT) for propulsion applications in heavy duty machinery suffer from low efficiency when the primary and secondary units do not operate at their optimal efficiency point. This paper proposes a novel HT architecture that decouples the primary unit operating point from the load (i.e., external torque and rotational speed). This allows the primary unit to always operate at a more favorable point, while maintaining roughly the same energy efficiency for the secondary unit, resulting in an overall increase of the total HT efficiency. Essentially, the decoupling is achieved by using a hydraulic accumulator to allow the primary unit to follow a reference pressure instead of a reference flow, like in secondary controlled HTs. This is achieved by controlling the angular velocity of the secondary unit by using another rotary actuator connected in the same shaft of the secondary unit. The paper details the architecture design, the component sizing and the power flow management. To assess the energy efficiency advantage of the proposed solution, the reference case of the basecutter system of a sugarcane harvester is considered. A lumped-parameter model for both the baseline commercial solution, validated based on available experimental data, and for the proposed systems were developed. Results for a realistic drive-cycle show a 7% reduction in energy consumption compared to baseline HT used in the reference machine, thus proving the efficacy of the proposed system. Elena Menegatti: Advancing Hydrogen Engine Powered Excavators: A Path to Energy-Efficient and Clean Construction Machinery Abstract: Today’s off-road vehicles rely on expensive engine aftertreatment systems in an attempt to meet stringent emissions standards, increasing costs and reducing installation space, providing an opportunity to explore alternative technologies, such as hydrogen engines. Off-road vehicles such as excavators, are characterized by harsh and rapidly fluctuating loads, to which the engine must be able to respond rapidly without critical speed drops. Because hydrogen engine’s torque response is slower than diesel, operating such a slow prime mover with conventional hydraulic systems currently on the market becomes challenging. Due to the limited academic research on off-road vehicles powered by hydrogen engines, this study aims to investigate the optimal design of a proposed hydraulic architecture capable of being gentle on the prime mover, to allow the hydrogen engine to meet the severe duty cycle requirements of off-road machines, while also improving the hydraulics’ system efficiency. This study is performed on a 24 ton. excavator, where the proposed fluid power solution is modeled in MATLAB/Simulink environment. By modeling an optimal interaction between the hydraulic system and the prime mover, it is demonstrated that the proposed solution allows for the operation of a hydrogen engine of the same displacement as its counterpart diesel in an excavator, greatly reducing fuel consumption and achieving CO2 emissions abatement.
12:00 PM - 1:00 PM WALC 1121	Lunch
1:00 PM - 2:40 PM WALC 1132	Session C: Electrification (Chair: TBD) Seshan Calapatti Suresh: A Thermal Simulation of Integrated Electro Hydraulic Actuator (iEHA) Abstract: Electrification of hydraulics is a promising option to address increasing emission restrictive regulation, it also provides a smoother transition to battery operated machine. However, Electro Hydraulic Actuators are generally thermally limited, especially in the case of a fully integrated actuator. Therefore, this study aimed at performing a thermal simulation of both the hydraulic components and the electric motor. Furthermore, this study concentrated on an EHA architecture where the return flow from the actuator was used to cool the electric motor. The outcome of this study demonstrates that using the return flow to cool the electric motor is not only feasible but is a compact and efficient way of cooling. Jacob Joseph Lengacher: Rationale and Design for Joint Electric – Hydraulic Supply for Agricultural Applications Abstract: A growing population and increased interest in environmentally friendly machinery lead naturally to a need for agricultural machines that are both more capable and more efficient in their use of energy. Agricultural machines have traditionally used throttling-based hydraulic systems to supply their working implements, leading to very inefficient behavior. One potential answer to this problem is the replacement of these systems with electrical ones. As a result, electric and hydraulic actuation systems are often viewed in opposition to one another. This is not the case, however. Electrical systems are efficient and straightforward to control, but are expensive, bulky, and sensitive to difficult environments. Hydraulic systems, in contrast, are compact, robust, and cost effective but have traditionally relied on inefficient throttling-based control schemes. This work aims to demonstrate that a combination of the two technologies aiming to utilize the strengths of one to cover the other’s weakness can result in a system arrangement that is both efficient and practical for implementation on real machines. To accomplish this, this work proposes one such system, designed for the case of an agriculture tractor / planter system. This system supplies base power hydraulically and uses an electrically powered pump to supply outlying high pressure actuators. Two control schemes for this architecture are proposed, one prioritizing system efficiency and one prioritizing component efficiency. The proposed architecture is then implemented on a full-scale reference machine and tested in realistic planting conditions. These tests demonstrate a 40% reduction in power consumption by the implement for the most common operating condition, demonstrating the efficiency potential of joint electric – hydraulic actuation. Nathan Allen Featherstone: Closed-Circuit EHA for Skidsteer Linear Functions Utilizing Continuous Contact Gear Pump Technology for Low Noise Leonardo Franquilino: STUDY ON HYDRAULIC ARCHITECTURES FOR ELECTRIFIED SKID-STEER LOADERS Abstract: Electrification of HDDMs emerges as a promising option to address increasing restrictions on gas emissions. However, given the inherent inefficiency of traditional hydraulic systems for mobile applications, a direct substitution of a diesel engine with a battery-electric motor would result in substantially reduced operating times. Solutions for high-efficiency hydraulic systems have been studied by academia and OEMs (e.g., EHA, DC, EMA, gravity self-balancing). Nonetheless, few solutions are offered in the market due to high implementation costs and space constraints. Therefore, this paper presents a comprehensive study using a simulation-based approach to determine the optimal hydraulic architecture for an electrified 5-ton compact track loader loader, encompassing all hydraulic working functions and utilizing a standardized duty cycle for energy efficiency comparison. The outcomes of the project demonstrate the capability to reduce total energy consumption by up to 29.2% and decrease installed pump displacement by up to 13%, without altering the performance. Scott Sudhoff: The Transverse Homopolar Machine: A More Robust Alternative to the Permanent Magnet AC Machine
2:40 PM - 3:00 PM WALC 1121	Coffee Break
3:00 PM - 5:00 PM	Lab Tour on Campus
5:00 PM - 6:00 PM	Travel to Dinner
6:00 PM - 8:00 PM	Dinner

Wednesday, May 14

7:30 AM - 8:30 AM WALC 1121	Breakfast
8:30 AM - 9:30 AM WALC 1132	Session D: Component Design (Chair: TBD) Parth Manoj Tawarawala: Multi-objective Optimization-based design of Crescent Internal Gear Machines for high-pressure hydraulic applications Abstract: With the growing importance of electrified hydraulic supply systems, with the ability to control prime mover speed, hydraulic gear machines have become increasingly more viable, and their design and modelling efforts have seen renewed interest. Among these pump types is the crescent internal gear machine (CIGM), often considered well-suited to these applications due to its quiet operation and high compactness while operating efficiently at medium and high-pressure applications. However, CIGMs are not commonly used because of their higher cost and design complexity than other gear pump types, contributing to a limited understanding of their design. Leveraging past modelling efforts, this work presents a procedure to parametrize the gearset and compensation features of a radially-ported CIGM and use a lumped parameter model embedded inside a genetic algorithm-based multi-objective optimization to design the CIGM, posed as a rigorous mathematical optimization problem. Using a lumped parameter model helps capture fluid dynamic phenomena like cavitation, pressure peaks, flow ripples, and frictional losses, which often get neglected in purely analytical formulations, while also allowing the design of pump features such as pressurization grooves and porting. These phenomena are usually undesirable and thus have been posed as objective functions to minimize. To demonstrate the procedure, an example optimization is run to generate a CIGM for operation in a generic hydraulic application, and the results show that design improvements over the baseline can be achieved through this procedure. Ratnam Dipakkumar Patel: SIMULATION INTEGRATED OPTIMIZATION BASED FEATURE DESIGN OF HYDRAULIC VANE MACHINE Abstract: Modern electrification trends have heightened the need for quieter hydraulic systems, as the elimination of internal-combustion-engine (ICE) noise makes pump-induced flow pulsations more noticeable. This paper presents a multi-objective optimization strategy for a dual-lip balanced vane pump, aiming to reduce flow ripple—a major contributor to noise—while maintaining or improving volumetric efficiency. The pump’s cam ring is parameterized using piecewise polynomial segments (3rd order in most sections) with enforced continuity constraints to ensure smooth vane motion and avoid chatter. Additionally, delivery-port grooves are incorporated as tunable triangular features, further softening transient pressure spikes. The optimization employs a lumped-parameter (LP) simulation to predict instantaneous flow rate and volumetric efficiency under multiple operating conditions. The LP model captures vane micromotions, fluid compressibility, and contact mechanics in a sufficiently accurate yet computationally efficient manner. Using a genetic algorithm within ModeFrontier’s MOGA-2, we systematically explore a high-dimensional design space (up to 12 ring-defining points plus groove-length variables). The objective function includes flow ripple variance and volumetric efficiency evaluated at three distinct operating points, providing robust performance across a range of speeds and pressures. Ishan Suvarna: Effects of Piston Cylinder Interface Fiction on Cylinder Block Valve Plate Interface Relability - A Numerical Analysis
9:30 AM - 10:30 AM WALC 1132	Session E: New Applications (Chair: TBD) Austin Luke Zapata: A Generalized Lumped-Parameter Model for Analyzing External Gear Machines with Shear-Thinning Operating Fluids Abstract: External gear machines are frequently used to transport non-Newtonian fluids in high pressure applications. Difficulties arise in their analysis and design due to the effect of viscoelasticity on the displacing action of the pump and the internal flow leakages. Methodologies covered in past works focused on three-dimensional CFD, but limited work has been done on a simulation tool for these effects which considers the radial micromotions of the gears. In this work, a fast lumped-parameter model for the simulation of external gear machines with non-Newtonian operating fluids is developed by dividing the pump into several control volumes and flow paths between them. A method of estimating flow for complex non-Newtonian fluid models is proposed as well as a novel Reynolds-type equation, and both are implemented within the model. Then, the mean flow and pressure ripple predicted by this model are compared with experiments to validate the methodology. The mean relative error of the model for both the steady-state and transient behavior are found to be under 8%. Jarrod Robins and John Murray: Demonstration of Pulse Flow Reverse Osmosis system with flow reversal capabilities Yan Gu: Advancing Legged Robotics: Research Progress and Perspectives on Fluid Power Integration
10:30 AM - 10:50 AM WALC 1121	Coffee Break
10:50 AM - 11:50 AM WALC 1132	IAB Meeting (Closed Door)
11:50 AM - 12:20 PM WALC 1132	Discussion on Future Activities
12:20 PM - 1:20 PM WALC 1121	Lunch