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The thermal performance of an engine coolant system is efficient when the engine head temperature is maintained within its optimum working range. For this, it is desired that air should not be entrapped in the coolant system which can lead to localized hot spots at critical locations. However, it is difficult to eliminate the trapped air pockets completely. So, the target is to minimize the entrapped air as much as possible during the coolant filling and deaeration processes, especially in major components such as the radiator, engine head, pump etc. The filling processes and duration are typically optimized in an engine test stand along with design changes for augmenting the coolant filling efficiency. However, it is expensive and time consuming to identify air entrapped locations in tests, decide on the filling strategy and make the design changes in the piping accordingly.

Scroll compressors are commonly used in HVAC and thermal management systems of electric and hybrid vehicles because of its high operating efficiency and smooth operation. The compressor is driven by an electric motor which forms a coupled system called an e-compressor unit. The refrigerant cools the motor before entering the scroll compressor. At different operating conditions of the vehicle, the change in power of the motor alters the refrigerant temperature and hence affecting the compressor’s performance. In the present work, 3D Conjugate Heat Transfer simulation of an e-compressor is performed as a complete unit with flow and heat transfer through the motor and compressor. A novel mixed timescale approach for the heat transfer has been developed to simulate the effect of thermal loads on the performance of the compressor. These performance parameters include the outlet temperature, volumetric efficiency, and discharge flow rate of the compressor.

Water wading tests are commonly performed for vehicles to ensure the functional integrity of different under-hood components at different water depths. This test has its relevance in both conventional Internal Combustion (IC) engine-based vehicles and Electric Vehicles (EVs). In IC engines, it is important for designing the Air Induction System (AIS), and for EVs, it helps to check the wetting of critical electrical and electronic components. The experimental setup for this test includes a long water tunnel where the car enters and exits the pool of water through a ramp. This work is an extension of the work done by Varshney et al. [6] where the Moving Reference Frame (MRF) technique was used to account for the motion of the car and the rotation of the wheels. The current work uses mesh morphing techniques to account for the motion of the vehicle and the rotation of the wheels that replicates the actual test conditions, including the inclination of the vehicle on the ramp.

Designing an efficient vehicle coolant system depends on meeting target coolant flow rate to different components with minimum energy consumption by coolant pump. The flow resistance across different components and hoses dictates the flow supplied to that branch which can affect the effectiveness of the coolant system. Hydraulic tests are conducted to understand the system design for component flow delivery and pressure drops and assess necessary changes to better distribute the coolant flow from the pump. The current study highlights the ability of a complete 3D Computational Fluid Dynamics (CFD) simulation to effectively mimic a hydraulic test. The coolant circuit modeled in this simulation consists of an engine water-jacket, a thermostat valve, bypass valve, a coolant pump, a radiator, and flow path to certain auxiliary components like turbo charger, rear transmission oil cooler etc.

The present work deals with the 3-D, transient, system level CFD simulation of an automotive coolant system using a 3D CFD solver Simerics MP+®. The system includes actual CAD of radiator, cooling jacket, coolant pump, bypass valve and thermostat valve. This work is in continuation of the work done by Srinivasan et al. [1] where wax melting, conjugate heat transfer, Fluid Structure Interaction (FSI) of the valve had been solved. Thermostat valve was controlled by wax phase change model which also incorporates the hysteresis effect of wax melting and solidification. The previous work dealt with the simulation of complete cycle, opening, and closing of the thermostat valve system. Besides the physics considered in the previous study, the current model also includes the treatment of cavitation to account for the presence of dissolved gases and vaporization of the liquid coolant.

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+®.

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.

The standard capability of engine experimental studies is that ensemble averaged quantities like in-cylinder pressure from multiple cycles and emissions are reported and the cycle to cycle variation (CCV) of indicated mean effective pressure (IMEP) is captured from many consecutive combustion cycles for each test condition. However, obtaining 3D spatial distribution of all the relevant quantities such as fuel-air mixing, temperature, turbulence levels and emissions from such experiments is a challenging task. Computational Fluid Dynamics (CFD) simulations of engine flow and combustion can be used effectively to visualize such 3D spatial distributions. A dual fuel engine is considered in the current study, with manifold injected natural gas (NG) and direct injected diesel pilot for ignition.