Automotive Science and Engineering

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Kinematic synthesis of a trailing six-member mechanism has been carried out to achieve five precision points of an automotive steering mechanism. The inner wheel can be rotated up to forty five degrees with fair accuracy. Results show that the divergent end behavior of Ackermann Steering Mechanism has been overcome by the present mechanism. The work is similar to earlier work by the present author. But the present mechanism is a trailing mechanism instead of a leading one. This helps to eliminate the spur gears used earlier to bring the mechanism on the rear side of the front axle.

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This paper presents a force field concept for guiding a vehicle at a high speed maneuver. This method is 
similar to potential field method. In this paper, motion constrains like vehicles velocity, distance to obstacle
and tire conditions and such lane change conditions as zero slop condition and zero lateral acceleration are
discussed. After that, possible equations as vehicles path are investigated. Comparing advantages and
disadvantages of 7th, 11th degree and a few other equations, followed by single mass and bicycle models
lead to an improved method, which is presented in this paper. 

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A comparative full life cycle assessment of a gasoline vehicle and a fuel cell vehicle (FCV) with five different fuel cycles including steam methane reforming (SMR), coal gasification, photovoltaic (PV), solar thermal, and grid-based electrolysis is presented in this paper. The results show that the total greenhouse gas emissions (GHG) are mainly found in the materials production and the component manufacturing stages of the FCV. Among various hydrogen production methods, the FCV with PV electrolysis has the lowest GHG emissions of 0.13 kg CO₂ eq./km. The total GHG emissions of the gasoline vehicle are estimated as 0.30 kg CO₂ eq./km mainly from the operation stage. An uncertainty analysis is carried out to assess the effects of variations of different input parameters on the total emissions. With a 95% level of confidence, the total emissions of the FCV with PV electrolysis is 0.18±0.05 kg CO₂ eq./km. The component manufacturing and assembly stage drives the total GHG emissions uncertainty the most.

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Erosive wear damage is common damage in the bearing shell of engines which causes a change in bearing profile and affects the oil film pressure and durability of bearing shell. The objective of the present paper is to present an appropriate algorithm for prediction and failure analysis of wear in BE bearing of engines using the Elasto-HydroDynamic (EHD) model. The mentioned model incorporating a mass-conserving algorithm is utilized to compute the lubrication characteristics of bearing, such as minimum oil film thickness and maximum oil film pressure. In EHD analysis, bearing housing is modeled by the finite element method to consider the bearing deformation. To estimate the wear volume, a code was written in MATLAB^Ò software which modifies the bearing profile and surface roughness during the analysis. A modified Archard model is used to model the lubricated sliding wear of rough contacting surface. Change in bearing surface roughness due to wear is modeled by the Abbot curve. Finally wear damage progression of BE bearing during engine operation is calculated and the results are thoroughly discussed. The numerical simulation results confirm that the wear rate at the initial stage of engine running is significant. It is concluded that wear adapts the bearing geometry in proper condition and improves the contact problem at the edges of bearing.

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In this paper, an adaptive cruise control system is designed that is controlled by a neural network model. This neural network model is trained with data resulting from the simulation of a multi-objective nonlinear predictive adaptive cruise control system. For this purpose, first, an adaptive cruise control system was designed using the concept of model predictive control based on a nonlinear model to maintain the desired speed of the driver, maintain a safe distance with the car in front, reducing fuel consumption and increasing ride comfort. Due to the time-consuming computations in predictive control systems and the consequent need for powerful and expensive hardware, it was decided to use the extracted data from the simulation of this designed cruise control system to train a neural network model and use this model to achieve control objectives instead of the predictive controller. Using the neural network model in the cruise control system, despite a significant reduction in computation time, the control objectives were well achieved, and in fact a combination of model predictive controller accuracy and neural network controller speed was used.

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Brakes are a vital, prime, and accident preventive part of any motor vehicle. Brakes help in controlling the vehicle speed when needed by changing the kinetic energy and potential energy into thermal energy. In this work, we have found out temperature distribution, deformation distribution, equivalent stress distribution, and equivalent strain distribution by varying the number of vanes in a ventilated disc brake, considering the coupled thermal and structural field in transient conditions, and compared the results to find out the best possible design. We have considered the disc rotor’s material as grey cast iron and the disc pad’s material as carbon fiber reinforced carbon matrix. It has been found out that with an increase in the number of vanes, there is a reduction in the maximum deformation, maximum stress, and maximum strain and there is a slight increase in the maximum temperature during the whole simulation. A disc rotor with 18 vanes is found to be the best possible design among all 5 designs considered in this paper.

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In recent years, the automotive industry has experienced a dramatic mutation in the develop ment of electric vehicles. One of the most important aspects of this type of vehicle is its thermal management. Among the various parts of an electric vehicle that are subjected to thermal management, the battery is of particular importance. Battery cell temperatures may exceed the allowable range due to continuous and high-pressure operation and various weather conditions, and this, in addition to performance, severely affects battery life. Therefore, the appropriate cooling system is essential. In this research, the most common methods of battery cooling are investigated. First, three-dimensional thermal analysis on the battery is performed using the computational fluid dynamics method in transient and steady-state phases.  Then, the effect of changing the cooling flow rate on the maximum temperature of the battery cell as well as the temperature difference of the cells in the battery pack is investigated. The effect of changing inlet coolant temperature change on battery cell temperature distribution is also investigated. The results show that by increasing the flow rate from 0.5 to 1.2 liter per minute, the maximum temperature in the battery pack and the temperature difference between the cells decrease to 44.4 and 2.51 ° C, respectively. Also, by changing the temperature of the inlet coolant from 15 to 30 ° C, the maximum temperature in the battery pack increases up to 42.2 ° C and the temperature difference is negligible.