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Positive displacement pumps are key components in automotive and hydraulic fluid systems, often serving as the primary power source and a major source of noise in both on-highway and off-highway vehicles. Specifically, gerotor pumps are widely utilized in vehicle coolant, lubricating, and other fluid systems for both conventional and electric powertrains. This study introduces a novel method for predicting noise in gerotor pumps by combining a Computational Acoustics (CA) approach with a 3D Computational Fluid Dynamics (CFD) approach, both implemented in the Simerics–MP+ code. The CFD simulation includes the detailed transient motion of the rotors (including related mesh motion) and models the intricate cavitation/air release phenomena at varying pump speeds. The acoustic simulation employs a Ffowcs–Williams Hawkings (FW–H) integral formulation to predict sound generation and propagation based on the detailed flow field predictions from the CFD model.

This paper reports on a novel three-dimensional computational fluid dynamics (CFD) and heat transfer coupled methodology for analyzing piston cooling using oil jets. The method primarily consists of models of the fluid and the solid domains that are thermally coupled to one another. One of the models is a crank angle transient, three-dimensional, multiphase, volume of fluid (VOF) CFD model of the fluid behind the reciprocating piston consisting of the piston jet and crankcase gases. This model is coupled to a piston solid model. The piston motion and heat transfer from the piston to the liner are rigorously accounted for. The combustion heat flux on the piston surface was an input to the current analysis as a boundary condition. All simulations were performed using the commercial CFD software Simerics MP+. The developed method is applied to three DI Diesel engine pistons, one piston without a cooling gallery and two pistons with cooling galleries.

This paper details a comprehensive CFD study of all three variants of the DrivAer car geometries: Fastback, Notchback and Estate configurations. The most realistic geometry was chosen for each of the variants; with detailed underbody, wheels and mirrors. In addition to the closed-grille standard DrivAer models, the open-grille variant has also been simulated. Simulations are performed and compared with experiments both with and without ground simulation. Mesh generation was performed without surface alterations (e.g. wrapping) using a novel Binary-Tree automatic unstructured mesher. All simulations were performed using an enhanced k-ε RANS turbulence model within Simerics MP+. A consistent modeling methodology was developed that was rigorously applied to all variants of the DrivAer model and the simulations are shown to have consistently good agreement with experimental measurements.

External gear pumps are positive displacement devices which perform with excellent efficiencies over a wide load and speed range. This wide range of performance is primarily due to micron-level leakage gaps in such machines which prevent large leakages at increasing loads. The present paper details a novel approach implemented in the commercial CFD tool PumpLinx that can capture the details of the micron level gaps, and model such machines accurately. The steps in creation of the model from original CAD geometry are described. In particular, the CFD mesh is created using a specialized template structured meshing method within PumpLinx especially created for external gear pumps and motors. This makes process of mesh creation and flow solution through complicated geometries of a gear pump efficient and streamlined.

This paper details the capability of PumpLinx® and Simerics® in simulating both Steady-State (Multiple Reference Frame) and transient, three dimensional torque converter performance and predicting the coupling point in a closed torque converter system in automatic transmission. The focuses of the simulation are in predicting the performance characteristics of the torque converters at different turbine to impeller rotating speeds (speed ratios) for 7 different torque converter designs and determine the coupling point at 70°C temperature. The computational domain includes the complex 3D design of all the impeller, turbine and reactor blades, the path ways that the oil travels between the above three components and the leakage gaps between these components. The physics captured in the simulation include the turbulence in the flow field and the rigorous treatment of the Fluid Structure Interaction (FSI) for the one-way free wheel reactor in predicting coupling point.

This paper reports on a comprehensive, crank-angle transient, three dimensional, computational fluid dynamics (CFD) model of the complete lubrication system of a multi-cylinder engine using the CFD software Simerics-Sys / PumpLinx. This work represents an advance in system-level modeling of the engine lubrication system over the current state of the art of one-dimensional models. The model was applied to a 16 cylinder, reciprocating internal combustion engine lubrication system. The computational domain includes the positive displacement gear pump, the pressure regulation valve, bearings, piston pins, piston cooling jets, the oil cooler, the oil filter etc… The motion of the regulation valve was predicted by strongly coupling a rigorous force balance on the valve to the flow.

This study introduces a method to examine the flow path of the lubricant inside a planetary gearset of an automatic transmission. A typical planetary gearbox has several load bearing elements which are in relative sliding motion to each other which causes heat to be released. The major sources of friction as well as heat are the meshing teeth between gears (sun/planet, planet/ring), thrust washers, thrust bearings and needle bearings. The lubricant performs the vital function of both lubricating these sliding interfaces and cooling these sources of heat, thereby preventing failure of the gearbox. The exact flow path that the lubricant takes inside a planetary gearset is unknown. Since the gearset is primarily splash lubricated, it is also not known how much lubricant reaches critical areas. A method is developed using computational fluid dynamic techniques to enable comprehensive flow and thermal analysis and visualization of an automatic transmission assembly.