Carbon Composites (CFRP) have been touted to be an essential component of future automobiles due to their mechanical properties and lightweight. CFRP has been adopted successfully for secondary and primary structures in Aerospace industry. In Automobiles, they are incorporated in models like the BMW i-series. CFRP suffers from 2 major problems. Delamination of Composites leads to catastrophic and rapid failure which could be dangerous in passenger vehicles. Delamination occurs whenever there is a shock on the composite. Secondly, Composites need regular expensive maintenance to ensure that the material is intact and will not compromise passenger safety. Carbon Nanotubes in composites have shown a substantial increase in delamination resistance. A 0.1wt% addition of HiPCO® Single-walled Carbon Nanotube provides both self-sensing and improved fracture resistance.
In sheet metal painting for various applications like Tractor, Automobile, most attractive coating is metallic paints and it is widely applied using 3 coats 2 bake or 3 coat 1 bake technology. Both options, results in high energy consumption, higher production throughput time & lower productivity in manufacturing process. During various brainstorming & sustainable initiatives, paint application process was identified for alternative thinking to reduce burden on environment & save energy. Various other industry benchmarking & field performance requirement studies helped us identify the critical to quality parameters. We worked jointly with supplier to develop mono-coat system without compromising the performance & aesthetical properties. This results in achieving better productivity, elimination of two paint layers, substantial reduction in volatile organic content, elimination of one baking cycle and energy saving.
In this paper, mold in color diamond white ASA material has been explored for front bumper grill, fender arch extension and hinge cover applications. Other than aesthetic requirements, these parts have precise fitment requirement under sun load condition in real world usage profile. Structural durability of the design was validated by virtual engineering. Part design and material combinations with better tooling design iterations were analysed by using mold flow analysis. Complete product performances were validated for predefined key test metrics such as structural durability, thermal aging, cold impact, scratch resistance, and weathering criteria. This part met required specification. This mold in color ASA material-based parts has various benefits such as environmentally friendly manufacturing by eliminating environmental issues of coating, easily recycled, and faster part production because intended color achieved in one step during molding.
Electric passenger car with floor battery usually have its front boot space empty and the space is used as additional luggage storage. Since it is completely closed, it is an adding factor to the drag coefficient of the vehicle. This space can be utilized to capture the wind energy to reduce the drag coefficient and generate electricity. Based on this, the objective of the work is to perform an aerodynamic analysis of an electric passenger car using wind turbine placed at the front. An active front grill shutters will be used to optimize the aerodynamic drag at different vehicle speeds. Initially the aerodynamic analysis of a basic electric car model is performed and then it is validated with the scaled model by using wind tunnel testing. The modified model with a wind turbine and an active grill shutters is analyzed, considering different parameters such as number of turbine blades, height of wind turbine, angle of attack, vehicle speed (60-120 kmph).
Any physical body being propelled through the air has drag associated with it. Drag will be created on the surface of the vehicle due to the flow separation at the rear end. In aerodynamics the flow separation can often result in increased drag particularly pressure drag, to delay the flow separation, the vortex generators are used on the roof end of the vehicle just before the point of flow separation. The objective of this project is to perform aerodynamic analysis of commercial vehicle using active vortex generators concept. First, the aerodynamic analysis of a baseline commercial vehicle model is performed and same is validated with the scaled model by using a wind tunnel test. Further analysis has been done by using active vortex generators concept with variation of angle of attacks for vehicle speed of 50, 70, 90 kmph. Also, analysis has been carried out for six different yaw angles. The simulation is carried out with the use of ANSYS Fluent.
Active aerodynamics can be defined as the concept of reducing drag by making real-time changes to certain devices such that it modifies the airflow around a vehicle. Using such devices also have the added advantages of improving ergonomics and performance along with aesthetics. A significant reduction in fuel consumption can also be seen when using such devices. The objective of this work is to reduce drag acting on a passenger car using the concept of active aerodynamics with grill shutters and air dams. First, analysis has been carried out on a baseline passenger car and further simulated using active grill shutters and air dams for vehicle speed ranging from 60 kmph to 120 kmph, with each active device open from 0° to 90°. The improved model obtained is then subjected to variations in yaw angle ranging from -18° to +18°. The optimized model is then validated for a scaled down prototype in a wind tunnel.
A high impetus from Government on road infrastructure development, is giving a fillip to passenger CV space. This has resulted in making the passenger CV segment lucrative enough, thereby pulling in many operators in the business. The quality of road has immensely improved over a decade, as a result of which the average speed and hence the quantum of distance covered by passenger buses has increased significantly. People are preferring to travel in buses over trains, owing to at par ticket cost, high availability, reduced travel time and also improved level of comfort. Aligned to the market need and the trend, OEM's are offering buses with capable powertrains to cater the need of speed, reduced trip time as well as a lot of attention is also being paid to tune in the comfort level for long hauls. A big chunk of passenger travel is catered by the bus operators especially during major festivals in India.
The study aims to evaluate the lateral stability of tractor-front end loader system in consideration with difficult work conditions based on various loader bucket lifting heights from ground while driving a system on transversal slopes. In the proposed method the centre of gravity of tractor-front end loader system was calculated and analysed to evaluate the transversal overturning of the system. This overturning of the system was analysed by applying mathematical equations presented in past studies and compared with the newly developed prediction model for 3 test tractors of 25 HP. The excel spreadsheet comprised of mathematical equations used to calculate the Tractor Stability Index (TSI) on transverse slope with respect to loader bucket height and payload in dynamic condition. A criterion has been defined to categorize the Tractor Stability Index (TSI) poor to excellent on a scale of 0 to 4 where <0 being the very poor, 0-2 Poor, 2-4 Good and >4 being the excellent.
Objective This paper explores the usage of Altair simulation driven optimisation process, Front Suspension hard points of a sedan Car model are optimised for specific target toe curves using MotionView, MotionSolve and HyperStudy This process gives the optimal hard point values to match the target curves without much iterations. Methodology Parametric Multibody model of the front end of sedan is built in MotionView. To Carry out optimisation HyperStudy is used where few of the suspension hard points which affect the toe curves are chosen as design variable. For the chosen Design variables upper and lower bound limits are specified. Ride, Roll and lateral force tests are performed. Optimisation is performed using HyperStudy where it iterates the suspension hard points to match the target toe curves. Each iteration response can be visualized in HyperStudy and can be compared with the target toe curve.
Objective Automotive sector is rapidly moving towards electric vehicle. BLDC motor is gaining popularity in the field of electric vehicle due to its high torque to weight ratio and simple control. In this paper we will focus on Switching loss characterization of 3 kW GaN based BLDC drive for electric vehicle. To improve efficiency of drive gallium-nitride based power transistor is used instead of Si MOSFET. GaN devices enable the design of inverter at higher frequencies with improved power density and efficiency as compared to traditional Si MOSFETs. Methodology In this paper commercially available GaN devices compared with Si MOSFETs. The power devices, which are selected for the performance comparison, are EPC2022 GaN by EPC, GS61008P GaN by Gan System and SiDR668DP Si MOSFET by Vishay. The Switching losses analytically predicted in MATHCAD tool and then compared with SPICE simulation losses. Double pulse test circuit is used to find out power losses of power transistors.
Two wheelers are the major mode of single transport in the metros of India. They contribute about 70 % of the auto market unit wise. Also it is proved from the research that for per unit energy consumption they contribute more to the environment emission. Conventional IC engine based energy supply unit can be replaced with an electric DC motor with chargeable battery as the energy source for the two wheelers present in the market. In the current research, engine is replaced with the motor, batteries and controller. The above system is placed on the space emptied by the conventional engine, The design developed is tested on different gradients for identifying the motor torque for minimum and maximum resistances available on the road. The paper provides an insight on the of the torque requirements based on variable resistances required for two wheelers. Also the system will be used as a retrofit for the existing IC engine bikes to be converted in electric bikes.
Role of Wheel and underbody Aerodynamics of vehicle in the formation of drag forces is detrimental to the fuel (energy) consumption during the course of operation at high velocities. This paper deals with the CFD simulation of the flow around the wheels of a bus with different wheel housing geometry and pattern. Based on benchmarking a model of a bus is selected and analysis is performed. The aerodynamic drag coefficient is obtained and turbulence around wheels is observed using ANSYS Fluent CFD simulation for different combinations of wheel-housing- at the front wheels, at the rear wheels and both in the front and rear wheels. The drag force is recorded and corresponding influence on energy consumption on an Electric Bus is evaluated mathematically. A comparison is drawn between energy consumption of bus body without wheel housing and bus body with wheel housing. The result shows a significant reduction in drag coefficient and fuel consumption.
Title Development of a Graphical User Interface (GUI) Based Tool for Vehicle Dynamics Evaluation Authors Mr. Shubham Kedia, Dr. Divyanshu Joshi, Dr. Muthiah Saravanan Mahindra Research Valley, Mahindra & Mahindra, Chennai Objective Objective metrics for evaluation of major vehicle dynamics performance attributes i.e. ride, handling and steering are required to compare, validate and optimize dynamic behavior of vehicles. Some of these objective metrics are recommended and defined by ISO and SAE, which involve data processing, statistical analysis and complex mathematical operations on acquired data, through simulations or experimental testing. Due to the complexity of operations and volume of data, evaluation is often time consuming and tedious. Process automation using existing tools such as MS Excel, nCode, Siemens LMS, etc. includes several limitations and challenges, which make it cumbersome to implement.
OBJECTIVE Race vehicles are designed to achieve higher lateral acceleration arising at cornering conditions. A focused study on the steady state handling of the car is essential for the analysis of such conditions. The transient response analysis of the car is also equally important to achieve best driver-car relationship and to quantify handling in the range suitable for a racing car. This research aims to investigate the design parameters responsible for the transient characteristics and optimize those design parameters. This research work examines the time-based analysis of the problem to truly capture the non-linear dynamics. Apart from tires, chassis can be tuned to optimize vehicle handling and hence the response times. METHODOLOGY To start with, the system is modelled with governing parameters and simulation is carried out to set baseline configurations. Steady state and transient handling simulations run independent of each other with independent logic, coded on MATLAB.
Research Objective The importance of evaluating ride comfort with high degrees of accuracy objectively and its correlation with subjective perception is increasing day by day because of the long duration of the driving experience. The complex motion of the vehicle which is the combination of heave, roll and pitch motion is responsible for causing extreme uneasiness to the driver as well as the passenger. In this paper, ride comfort evaluation is done on the highway with similar traffic conditions with the help of Vibration Dose Value Analysis, Suspension Working Space and Ride Diagram methods for two hatchbacks and its correlation with the complex motion like choppiness of the vehicle is established that will help us to enhance the driver ride experience. Methodology The ride testing is performed for two hatchbacks on a highway road with different kinds of terrain ranging from highly uneven road roughness to moderately smooth surface for a speed range of 60-100 kmph.
Objective To achieve better fuel economy and reduced carbon footprint, OEMs are reducing the sprung and unsprung mass. This translates into a reduction in stiffness which profoundly deteriorates the handling/road holding characteristics of the vehicle. To model these changes in stiffness, modifications are made to suspension roll stiffness at the front and rear. This study compares different configurations of roll stiffness and evaluates vehicle behavior using frequency response characteristics and phase change of Yaw Gain recorded. The present work associates acquired data with subjective feedback to outline the shift in vehicle balance emerging from a variation of sprung and unsprung mass ratio. Methodology To study the frequency response characteristics of the vehicle, the pulse input is chosen for this. An ideal pulse input’s Fourier transform represents constant amplitude over all the frequency ranges. By giving a single input, the system is subjected to a range of frequencies.
The present work involves Machine Learning (ML) based Multi-objective Multidisciplinary Design Optimization (MMDO) for lightweighting the automotive structures. The challenge in deployment of MMDO algorithms in solving real-world automotive structural design problems is the enormous time involved in solving full vehicle finite element models that involve large number of design variables and multiple performance constraints pertaining to vehicle dynamics, durability, crash and NVH domains. With the availability of powerful workstations and using the advanced Computer Aided Engineering (CAE) tools, it has become possible to generate huge sets of simulation data pertaining to multiple domains.
Tyre Traction Trailer is a device designed to find the Peak Brake co-efficient of C2 and C3 tyre as per ECE R117. The trailer is towed by the truck and is braked suddenly to evaluate braking co-efficient of specimen tyre. It is a single wheel trailer equipped with load cell to capture tire loads (Normal and longitudinal)while braking. Traction Trailer is modelled in MSC Adams and rigid body simulation is carried out for static stability of the system. Dynamic simulations were performed to understand locking of wheels during braking. Body frame was further modelled as flex body to perform structural analysis of the frame. The paper contains stress and deformation plots of trailer Structure under various loading conditions, change in Centre of gravity, weight transfer and forces on springs during braking and cornering, plots of tractive and normal load on tyre during braking.
In the current commercial vehicles market, ride-comfort and handling are crucial parameters for the customer and end user. There are various aspects which determine the vehicle behaviour. One of aspects is the structural rigidity of the vehicle, which has its own effect on vehicle dynamics. To meet the required stiffness of the main structural component of the vehicle i.e. chassis frame, FEA analysis has to be done in current methodology. The number of iterations have to be done to build an appropriate model with low weight, which can meet the design requirements. At first, conceptual design mock-up unit is to be developed then FEA (CAE) analysis to be done on it. If any design criteria are not met, then this cycle repeats again until it fulfils the required stiffness. Today, the direct stiffness procedure is the basic principle of almost every FEA software package.