A gerotor pump is a positive displacement pump consisting of inner and outer rotors, with axis of inner rotor offset from axis of outer rotor. Both rotors rotate about their respective axes. The volume between the rotors changes dynamically, due to which suction and compression occurs. A gerotor pump may be subject to erosion due to cavitation. This paper details about the CFD methodology that has been used to capture cavitation bubbles which might form during the operation of gerotor pump. A full scale (3D) transient CFD model for gerotor pump has been developed using commercial CFD code ANSYS FLUENT. The most challenging part of this CFD flow modeling is to create a dynamic volume mesh that perfectly represents the dynamically changing rotor fluid volume of the gerotor pump. Two different approaches have been used to model this dynamic mesh analysis in the Ansys Fluent tool - one method by using the traditional UDF script and, another method by using Python automation script.
The present study discusses about the determination of the Seal drag force in the application where elastomeric seal is used with metallic interface in the presence of different fluids. An analytical model was constructed to predict the seal drag force and experimental test was performed to check the fidelity of the analytical model. A Design of Experiment (DoE) was utilized to perform experimental test considering different factors affecting the Seal drag force. Statistical tools such as Test for Equal Variances and One way Analysis of Variance (ANOVA) were used to draw inferences for population based on samples tested in the DoE test. It was observed that Glycol based fluids lead to lubricant wash off resulting into increased seal drag force. Additionally, non-lubricated seals tend to show higher seal drag force as compared to lubricated seals. Keywords: Seal Drag, DoE, ANOVA
The objective of this study is to introduce and assess a computational tool designed to facilitate product development via sensory scores, which serve as a quantifiable representation of human sensory experiences. In the context of designing ride comfort performance, the specialized terminology—either technical or sensory—often served as a barrier to comprehension among the diverse set of specialists constituting the multidisciplinary team. In a previous study by the authors introduced a tool that incorporated a model of sensory performance, utilizing sensory scores as universally comprehensible metrics. However, the tool had yet to be appraised by a genuine cross-functional team. In this study, the tool underwent evaluation through a user-testing process involving twenty-five cross-functional team members engaged in the conceptual design phase at an automotive manufacturing company.
Multiple experimental studies were performed on galling intiation for variety of tooling materials, coatings and surface treatments, sheet materials with various surface textures and lubrication. Majority of studies were performed for small number of samples in laboratory conditions. In this paper, the methodology of screening experiment using different combinations of tooling configurations and sheet material in the lab followed by the high volume small scale U-bend performed in the progressive die on the mechanical press is discussed. The experimental study was performed to understand the effect of the interface between the sheet metal and the die surface on sheet metal flow during stamping operations. Aluminum sheet AA5754 2.5mm thick was used in this experimentation. The sheet was tested in laboratory conditions by pulling between two flat insert with controllable clamping force and through the drawbead system with variable radii of the female bead.
In this study, a novel selective matching logic for wheel/tire was proposed to reduce vehicle driving vibration caused by wheel/tire non-uniformity. Furthermore, validation of the new logic was performed via the matching simulation/in-line matching evaluation. The RFV theoretical model was established by considering the theoretical model of the existing references and the wheel/tire assembly mechanism, and the model was validated using ZF's HSU equipment used as standard equipment in the tire industry. The validity of the new matching logic was verified through matching simulation and mass production in-line evaluation. In conclusion, the novel logic presented in this paper has been effectively proven to reduce the RFV caused by wheel/tire, and it is being applied to mass production.
In the field of automotive aerodynamics, there's a consistent need for tools that effectively manage both rapid design changes and comprehensive simulations. The recent GPU code update to the PowerFLOW, Lattice Boltzmann simulation tool is an attempt to meet this need. An important feature of this update is the inclusion of the Sliding Mesh rotating reference frame, which improves rim modeling accuracy. This modification provides a clearer depiction of vehicle aerodynamics, aiming for balanced and efficient designs. The updated GPU solver has been tested with two main resolutions. First, a low-resolution aerodynamics scheme which can assist designers and stylists in their initial stages of design. This setup aims to offer a rapid iterative design process. In addition, for more detailed analysis, full-scale resolution simulation setups are possible with the NVIDIA A100's 80GB memory capacity.
The study and application of Topology Optimization (TO) has experienced great maturity in recent years, presenting itself as a highly influential and sought-after design tool in both the automotive and aerospace industries. TO has experienced development from single material topology optimization (SMTO) to multi-material topology optimization (MMTO), where material selection is simultaneously optimized with material existence. Today, MMTO for standard structural optimization responses are well supported. An additional and vital response in the design of structures is that of stress. Stress-driven or stress-controlled optimization techniques for SMTO are well understood and have been well-documented, evidenced by both published works and its availability in multiple commercial solvers. However, its integration into MMTO frameworks has not yet achieved reliable levels of accuracy and flexibility.
Model-based development is being introduced to shorten the development time of vehicle systems. Various model-based tools, including MATLAB/Simulink, have been introduced, and each vehicle part has model assets using different tools. This makes the system complex and reduces simulation efficiency because of the need for interfaces or converters when reusing model assets and combining parts. On the other hand, machine learning, in which neural nets are pre-trained to make inferences in real-time, is being applied to automatic driving and other applications, such as object recognition. This study constructed a system in which inputs and outputs given to a model are trained by neural nets, and the trained neural nets are combined on UML. A previous UML integration proposal is integrated C/C++ codes which are automatically generated from models. For this reason, the previous proposal had limited use of modeling tools with automatic code generation capabilities.
The integrity of isolation resistance of the xEV high-voltage subsystems is critically important to ensure the safety of vehicle occupants. As described in the regulation FMVSS 305, the isolation resistance is indirectly determined based on the measured voltages. The existing formula used for calculating the isolation resistance does not take into account the finite input-resistance of the voltage measurement equipment. The assumption of infinite input resistance of the voltage measurement equipment leads to significant error, which will be quantified in this paper. The proposed method in this paper includes the input-resistance and results in accurate calculation of isolation resistance. Both real-word data and simulation results will be included to verify the accuracy and the effectiveness of the proposed method.
The AutoDrive Challenge competition sponsored by General Motors and SAE gives undergraduate and graduate students an opportunity to get hands-on experience with autonomous vehicle technology and development as they work towards their degree. Michigan Technological University has participated in the AutoDrive Challenge since its inception in 2017 with students participating through MTU’s Robotic System Enterprise. The MathWorks Simulation Challenge has been a component of the competition since its second year, tasking students with the development of perception, control, and testing algorithms using MathWorks software products. This paper presents the pedagogical approach graduate student mentors used to enable students to build their understanding of autonomous vehicle concepts using familiar tools. This approach gives undergraduate students a productive experience with these systems that they may not have encountered in coursework within their academic program.
Recently, topology optimization (TO) has seen increased usage in the automotive industry as a numerical tool, greatly enhancing the accessibility and production-readiness of optimal, lightweight solutions. By natural extension of classic single material TO (SMTO), a wealth of research has been completed in multi-material TO (MMTO), enabling simultaneous determination of material selection and existence. MMTO is effective for linear static analyses, making use of structural responses that are continuously differentiable, giving itself to efficient gradient-based optimization engines. A structural response that is inherently nonlinear and transient, thus providing difficulty to the mainstay MMTO process, is that of crashworthiness. This paper presents a multi-objective MMTO framework considering crashworthiness using the equivalent static load (ESL) method. The ESL method uses a series of linear static sub-models to approximate the transient crashworthiness model.
This paper revised the current situation in development of the accelerated testing of automotive engineering that consists of the four following areas: 1.Field testing of the natural product. 2. Additional technology of separate testing in the laboratory on the basis of physical simulation of separate field conditions with using corresponding methods and equipment separately and conducting: safety testing, special programs of testing using digital simulation, special testing with changing certain parameters of environment, corrosion testing, etc. Both of the traditional testing developments above can be found in many magazines, journals, conferences presentations and proceedings. 3. Testing on the basis of digital (computer) simulation of product and/or field conditions. This area of testing ihas especially developed in the last dozen years. Many articles and presentations were published during this time. 4.
In the ever-evolving landscape of automotive technology, the need for robust security measures and dependable vehicle performance has become paramount with connected vehicle and autonomous driving. The Unified Diagnostics Services (UDS) protocol is the diagnostic communication layer between various vehicle components which serves as a critical interface for vehicle servicing and for software updates. Fuzz testing is a dynamic software testing technique that involves the barrage of unexpected and invalid inputs to uncover vulnerabilities and erratic behavior. This paper presents the implementation of fuzz testing methodologies on the UDS layer, revealing the potential vulnerabilities that could be exploited by malicious entities. By employing both open-source and commercial fuzzing tools and techniques, this paper simulates real-world scenarios to assess the UDS layer's resilience against anomalous data inputs.
A variety of structures under the influence for external force get excited due to resonance. This is because the frequency of external force and the natural frequency of the structure align with each other. This leads to high deformation which may cause damage to the integrity of the structure. There have been many applications of external devices to dampen the effects of this excitation in the structure such as Tuned mass dampers, Semi-Active and Active damper, which have been implemented in buildings, bridges and other fairly large structures. One of the methods used for active cancellation uses the principle of centrifugal forces generated due to rotation of an imbalance mass. This force helps countering the external excitation force coming into the structure.