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For an efficient automotive AC system it is very essential to ensure uninterrupted and consistent airflow and temperature at the vent exit to help achieve the comfortable cabin space. This certainly requires temperature sensor to position at lowest possible temperature on heat exchanger and uniform flow distribution over it. However the uneven distribution of airflow on evaporator entry face leads to lowest temperature and sometimes goes undetected. This causes the condensate to get freezed and then frosting occurs at the core surface. Eventually a substantial portion of evaporator face gets choked and gradually airflow reduces and evaporator exit air temperature shoots up. Hence it is very important to prevent the frosting on evaporator core so to have uninterrupted airflow and adequate cooling in the passenger compartment. The present paper investigates the reasons for frosting occurring in one of the hatchback vehicle in bench test.

The aim of this paper is to optimize flow distribution on various ports of the ventilation unit. To improve the passenger comfort, ventilation unit need to be redesigned to get the uniform distribution in all ducts. There were challenges for the design modification on the unit to meet the distribution. The major challenge was to meet the distribution on the duct outlet without doing any design changes on the ducts. Hence the adapter which is the intermediate part between the blower and duct assembly is modified and simulation is done on the various design changes by changing the design of the adaptor part. CFD analysis is carried out on the ventilation unit with iterative design changes and achieved the target airflow and distribution. The analysis has been carried out on STAR CCM+ software.

Numerous studies considering interaction between refrigerant and reed valve motion in positive displacement compressors have been cited in literature. CFD and FEA simulation tools have allowed modeling of fully coupled interaction of fluids and moving parts [1]. The present paper describes a simplified model of a multi-cylinder reciprocating piston compressor and estimation of pressure surge at high compressor speeds. The results show that the delayed discharge valve opening and closing causes surge in pressures due to formation of pressure waves. For the chosen geometry and operating conditions in the present paper, the characteristic travel time of such waves is much shorter (~ 0.2ms) as compared to longer response time of reed valves (> 1ms) owing to stiffness and exhibit delayed opening due to others factors too like stiction effect. These pressure surges may exceed the fatigue limit of reed valves and cause failures.

Less weight, structural integrity, good dynamic behavior, material selection, performance & energy consumption are important parameters while designing A/C components for EV applications. Structural integrity and dynamic behavior of these components is predicted by conducting dynamic analysis of A/C unit under standard vibration load test conditions. Material selection is another important point while designing A/C and simulation helps designer for proper material selection at initial design stage. Achieving required cooling capacity with less compressor power is another important factor while designing A/C unit and this is done by proper design changes on condenser and evaporator side with proper compressor selection. For this, CFD analysis helps to predict the air flow accurately with the given design parameters.

Heating, ventilation and air conditioning systems play a crucial role in our day-to-day activities. With rise in global warming, leading to climate change, HVAC unit is the need of the hour. With average temperatures on the rise, it is quite imperative that the unit provides better thermal comfort to the passengers. Off-road vehicles like tractor, is also no exclusion. Tractor drivers have to experience adverse weather conditions out in the open field. Thus it is quite fundamental that sufficient airflow reaches every point inside the driver cabin, ensuring proper cool-down. To ensure proper distribution of airflow inside the cabin, optimization of HVAC unit needs to be properly carried out. The present study shows how an HVAC of an off-road vehicle is properly optimized with the help of Computational Fluid Dynamics. STAR-CCM+ v2021.2.1 is used as solver for the simulation.

With the growing demand in passenger comfort and enhanced safety and high competitiveness in the automotive segment, automotive manufacturers are keen to launch the product flawlessly within short period of time. In that regard one of the areas related to safety of passengers which is windshield deicing, requires lot of attention and to be developed and certified well before the product launch. Computational fluid dynamics (CFD) helps in this regard to come up quickly with a feasible design solution. But with the conventional method of doing deicing requires lot of time and high cell count. Hence there is a requirement of developing a methodology which will shorten the simulation time and thus leading to shorter development time. One such development took place is in the multiphase models in CFD. The present study focuses in introducing a novel methodology for predicting the transient deicing pattern in an automotive windshield.

With the transition from Internal Combustion Engines Vehicles (ICEVs) to Electric or Hybrid Electric Vehicles (EVs/HEVs), most of the system aggregates and system parameters need to be redefined and recalibrated. This is mainly due to the change in power and transmission system. One of the critical system aggregates is heating ventilating and air-conditioning (HVAC) system as it directly impacts the car interior noise (other than passenger comfort) across all speed ranges. At low speed, interior noise becomes more annoying due to HVAC and electromagnetic noise from traction motor. However, at high speed other auxiliary noise sources are added up to the overall noise sources. Hence it becomes necessary to design and develop the HVAC system which should produce no abnormal noise and overall noise becomes low. The advancement of numerical simulation plays an important role in finalizing the HVAC design and also provides better insight of the products.

With the global competitiveness in automotive segment, vehicle manufacturers are facing steep competition in reducing the overall cost, development time without compromising the performance and quality. So the development of each aggregate, system and sub-system also need to be faster than ever before. Being an automotive AC manufacturer, it is quite obvious that the AC system should also be developed within short span of time. However it is quite imperative to meet or exceed the cooling requirement. Hence a novel approach of combining the 1-dimensional (1D) and 3-dimensional (3D) simulation is developed in order to evaluate and predict the cabin cool down before the actual prototypes are being made. The present study employs the combined approach of predicting the system level performance through 1-D simulation and predicting the airflow field inside the vehicle using 3D simulation. System level simulation was carried out in Kuli software.

The aim of this paper is to analyze Train Driver Cabin AC kit to improve performance of Rail AC unit. First CFD analysis has been carried out on the existing design to find the airflow on the condenser side. Based on the analysis result, design modification has been done to improve the air flow on the condenser side and thereby improving the cooling capacity of the unit. CAE analysis has been carried out to strengthen mount brackets of condenser fan. With the design changes, there is significant improvement found on the structural integrity. Modal frequency improved and dynamic stress been reduced. Based on final modified design, proto was developed, tested and found OK which further verified with CAE/CFD results.CAE analysis has been carried out using ABAQUS/Hypermesh software and CFD using STAR CCM+.

Indian Railways, often described as the “transport lifeline of the nation”, is the fourth largest railway network in the world, from suburbs to urban transit, the Indian rail network covers the length and breadth of the country. To make the journeys easier and memorable it is very much important to provide adequate comfort and easy access to every facilitates. For better comfort inside the coach as well as in the drivers’ cabin, air-conditioning system has to be quite effective and energy efficient. While it is too expensive to go with prototypes at the initial stage, numerical simulation comes very handy in helping and optimizing the unit and come out with viable design concept within very short time. The present study provides a methodology for the numerical simulation of a drivers’ cabin AC to determine the volumetric airflow rate. The unit is designed for the drivers’ cabin and it is mounted on roof.

In order to ensure a comfortable space inside the cabin, it is very essential to design an efficient heating ventilating and air-conditioning (HVAC) system which can deliver uniform temperature distribution at the exit. There are several factors which impact on uniformity of temperature distribution. Airflow distribution is one of the key parameter in deciding the effectiveness of temperature distribution. Kinematics links and linkage system typically termed as ‘mechanism’ is one of the critical sub-systems which greatly affects the airflow distribution. It is not the temperature uniformity but also the HVAC temperature linearity also depends on airflow distribution. Hence the design of mechanism is incomparably of paramount importance to achieve the desired level of airflow distribution at HVAC exit. The present paper describes the design methodology of automotive HVAC mechanism system.

Vehicle air conditioning and heating system is one of the most important part of an automobile system. Computational fluid Dynamics (CFD) is widely used to predict air flow rates and distribution in such Heating Ventilation and Air Conditioning (HVAC). Commercial CFD codes such as FLUENT and STAR-CCM+ are widely used in simulation for industrial research. But usage of these software comes with a heavy cost. Cost is one such parameter which industries try to bring down, without compromising on the deliverables in product development. OpenFOAM is one such license free, open source code that can be used to modify and compile its code based on the needs and the physics of the problem in hand. This study assessed the performance of airflow magnitude and distribution in an HVAC using OpenFOAM. The results between STAR-CCM+ and OpenFOAM were compared in terms of grid-independent solutions using various scalar and vector plots.