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During a vehicle drive cycle, the oil in the engine oil pan sloshes very vigorously due to the acceleration of the vehicle. This can cause the pickup tube in the engine oil pan to become uncovered from oil and exposed to air, which affects the lubrication pump performance. Engine oil pan sloshing is inherently a 3D problem as the free oil surface is constantly changing. Multi-dimensional Computational Fluid Dynamics (CFD) methods are very useful to simulate such problems with high detail and accuracy but are computationally very expensive. Part of the engine lubrication system, such as the pump, can be modelled in 1D which can predict accurate results at relatively high computational speeds. By utilizing the advantages of both 1D and 3D CFD models, a coupled 1D-3D simulation approach has been developed to capture the detailed oil sloshing phenomenon in SimericsMP+ and the system level simulation is conducted in GT-SUITE where 3D spatial data is not required.

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.

With the on- and off-road diesel engine emission regulations getting more stringent across the world, diesel aftertreatment systems are expected to deliver outstanding performance and reliability. These objectives should be met by fulfilling tight packaging constraints and incurring only modest material and testing costs. A major strategy for meeting these often conflicting requirements is the effective use of simulation tools such as computational fluid dynamics (CFD) in system design and performance evaluation. Prerequisites for using this CFD analysis-led-design approach, however, are knowledge of the confidence level of the predictions and knowledge of the appropriate transfer functions that establish the relationships between the measured performance parameters and model predictions. The primary aim of the present work is to develop statistically and physically relevant measures that assess the uniformity of flow in aftertreatment systems.

In gasoline engines, a scraper ring with a step on the bottom outer edge is widely used as a second ring. However, there lacks a fundamental understanding on the effects of this feature and its dimensions on oil transport. Inspired by observations from visualization experiments, this work combining computational fluid dynamics (CFD) and theoretical analysis shows that oil can be trapped in the space bordered by a second ring step and the chamfer of a piston third land. The trapped oil can be released to a liner when the piston is approaching the top dead center (TDC). This additional oil on the liner becomes a potential source of oil consumption. Such oil transport has been observed at typically less than 1500rpm. Since road vehicles often operate in this speed range, the newly-observed oil trapping and release can be closely associated with oil consumption in gasoline engines. In this work, a comprehensive study on oil trapping and release will be demonstrated.

A gasoline direct injection fuel spray was observed using a fired, optical access, square cross-section single cylinder research engine and high-speed video imaging. Spray interaction with the piston is described qualitatively, and the results are compared with Computational Fluid Dynamics (CFD) simulation results using KIVA-3V version 2. CFD simulations predicted that within the operating window for stratified charge operation, between 1% and 4% of the injected fuel would remain on the piston as a liquid film, dependent primarily on piston temperature. The experimental results support the CFD simulations qualitatively, but the amount of fuel film remaining on the piston appears to be under-predicted. High-speed video footage shows a vigorous spray impingement on the piston crown, resulting in vapor production.

This paper discusses the holistic approach of simulating a low pressure pump (LPP) including test stand flow dynamics. The simulation includes all lines and valves of the test stand representing realistic test operating conditions in the simulation. The capability to capture all line dynamics enables a robust design against resonances and delivers high-quality performance data. Comparison with actual test data agrees very well giving us confidence in the prediction capability of proposed method and CFD package used in the study. Despite the large spatial extent of the simulation domain, Simerics-MP+ (aka PumpLinx) is able to generate a feasible mesh, together with fast running speed, resulting in acceptable turn-around times. The ability to still model small gaps and clearance of the LPP very efficiently enables inclusion of realistic tolerances as experienced on hardware.

Metal foam with their high porosity and heat storage capacity can be combined with phase change materials to be a powerful heat storage device. Numerical simulations of metal foam behavior can be challenging due to their complex geometric patterns necessitating high mesh requirements. Furthermore, simulations of the inner workings of a metal foam heat exchanger comprising of a large number of individual metal foam canisters can be impossible. The objective of the current work is to develop a computational model using a proprietary CFD tool Simerics-MP/Simerics-MP+® to simulate the workings of a metal foam heat exchanger with phase change element. A heat transfer coefficient capturing this heat transfer between wax and metal is used to formulate the “simplified” mixture model. The versatility of the proposed model is in the universality of its application to any shape or structure of metal foam. The computational model developed is tested to replicate the results of the 3D simulation.

The oil flow rate in an automotive vane pump varies by virtue of the eccentricity between the inner rotor and the chamber wall. The movement of the chamber wall is facilitated by a ring-spring assembly which is pivoted and moves depending on the balance of system oil pressure and the pre-tensioned spring. In this paper, the ODE of kinetics of the solid piece spring motion is dynamically coupled with CFD simulation of oil flow in a vane pump. A re-meshing step is taken at every time step based on the update of the fluid domain which is determined from the ring position. The algorithm is implemented in the general purpose CFD code PumpLinx and applied to an automotive vane oil pump. The simulation results of pump performance curve are compared with the measurement data, together with the ring positions comparison. A very good agreement is observed between the simulation results and measurement data.

A numerical analysis of drag torque and cooling characteristics of a Multi-plate clutch pack with a circular pin fin shaped groove pattern is presented in this article. Simulations were performed using Simerics MP® platform to investigate the drag torque and heat transfer under various operating conditions. The performance characteristics of the circular pattern were later compared with various designs from the literature. Some of the groove pattern designs considered have been commonly used in transmission systems and some are from the patent literature. This study compares each design and later proposes the most efficient, that has the least drag and highest heat transfer characteristics.

Centrifugal pumps are widely used in different thermal fluid systems in automobile industries. Computational fluid dynamics (CFD) analysis of such a thermal fluid system depends on the accurate component modeling of the system components. This paper presents CFD analysis of a centrifugal pump with two different approaches: Transient (moving grid) and the steady state - Multiple Reference Frame (MRF) methods using a commercial CFD solver Simerics MP+®. In addition, flow and pressure drop data obtained using CFD simulations of a vehicle coolant hydraulic system was compared to results from rig test data. The Transient method incorporates the real motion of the pump blades geometry and temporal flow solutions are obtained for instantaneous positions of the blade geometry. In MRF approach, the flow governing equations for the stationary zone are solved in the absolute/inertial reference frame, whereas flow in the moving zone is solved in the relative/non-inertial reference frame.

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.

Diesel emission aftertreatment system is usually designed to meet stringent packaging constraints, rendering a difficult situation to achieve perfect flow distribution inside the catalytic unit. The non-uniform flow pattern leads to a mal-distribution of flow velocity, temperature, and gas species in catalyst unit. Some catalysts are exposed to harsh working environment, while the rest catalysts are underutilized. This lowers the efficiency of overall catalyst unit and thus requires an oversized system to meet emission requirements. The flow mal-distribution also accelerates the uneven catalyst degradation, lowering the system durability. Hence, a quantitative description of packaging impact on catalyst performance is critical to assess the system efficiency and durability. In the present work, a mapping method is developed to combine catalyst performance with computational fluid dynamics (CFD) simulation.

The present work deals with the development of a CFD method to simulate water fording/water wading for a passenger car. Water wading of automobiles in different water depths can lead to water ingestion into the air induction snorkel. This is unfavourable as this ingested water can cause the malfunction of the engine. This takes on an added importance when designing multi-terrain vehicles, where the interest could be in wading water effectively in many scenarios. The design of the snorkel, its position and height can be important in preventing water from entering the Air Induction System (AIS) and hence the engine. So, a water fording test of a vehicle is conducted to ensure the efficacy of the AIS snorkel in preventing water entering the AIS system. The ability of numerical simulations to effectively replicate testing performed in a long water tank is put to test in this paper. The CFD method development has been done using the commercial code, Simerics-MP+®.

An advanced exhaust aftertreatment system (ATS) for Tier 4 compliant locomotive applications was successfully designed and developed for use on Cummins QSK95 engines. The engine and ATS were introduced in late 2016. This system provided nitrogen oxides (NOx) reduction capability in excess of 95%. Vanadia-based selective catalytic reduction (V-SCR) extruded catalyst technology was chosen over other readily available component technologies such as diesel oxidation catalyst (DOC) or a combination of DOC and SCR systems to address the stringent Tier 4 standards. In addition to NOx reduction, substantial oxidation of gaseous hydrocarbons (HCs) from unburnt fuel and lubricating oil soluble organic fraction (SOF) was also achieved. This dual functionality (oxidation and reduction capability) was one of the key factors in adopting this technology as the prime path and rendering it suitable for the harsh locomotive application environment.

Selective catalytic reduction (SCR) is a promising technology for meeting the stringent requirements pertaining to NOx emissions. One of the most important requirements to achieve high DeNOx performance is to have a high uniformity of ammonia to NOx ratio (ANR) at the SCR catalyst inlet. Steady state 3D computational fluid dynamics (CFD) models are frequently used for predicting ANR spatial distribution but are not feasible for running a transient cycle like Federal Test Procedure (FTP). On the other hand, 1D kinetic models run in real time and can predict transient SCR performance but do not typically capture the effect of non-axial non-uniformities. In this work, two 3D to 1D coupling methods have been developed to predict transient SCR system performance, taking the effect of ANR non-uniformity into account. First is a probability density function (PDF) based approach and the second is a geometrical sector based approach.

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 paper reports on engineering insights that can be gained from a rigorous, transient, three-dimensional CFD analysis of the complete lubrication system of automotive internal combustion engines. Building such a model is a formidable task because the computational domain of such a model is vast and includes scores of bearings as well as components such as the pump, pressure relief valve, oil filter, oil cooler, piston cooling jets etc. Thus far, the only publication on 3D CFD analysis of an engine lubrication system was for a 16-cylinder engine in which the feasibility and the potential opportunities of such a model were demonstrated. The aim of this work is to cover four engineering topics of interest in a lubrication system: 1. Showcase the capability of the CFD tool to accurately, robustly and reliably predict the engine lube system performance of a wide variety of automotive engines with no reliance on tuning the inputs.

This paper reports on a transient, three-dimensional computational fluid dynamics (CFD) study of flow and heat transfer in the complete fuel system of an inline 6-cylinder, direct injection (DI) diesel engine used in commercial applications. The CFD software Simerics-MP+ was used for this purpose. Diesel engine development, to meet fuel economy and exhaust emission standards, requires the precise integration of each component in the fuel system in order to reliably deliver the fuel to the combustion chamber as a function of crank angle to the combustion chamber, at the specified injection pressure. Both the model set-up and run times are practical, thus the simulation tool can play a key role in the design and development of diesel engine fuel systems.