International Journal of Mechanical Engineering

7-14

Authors: S. Venkateswarlu, G. Narendra, B. Sriram Achari, G.V.Lahari, K.Umesh Chandra & S. Anwar Basha

Automobile chassis is one of the major elements of road motor vehicles. Normally automobile is divided into two parts they are Body and Chassis. Thus this chassis design and analysis form the most important stage of vehicle manufacturing. It is a basic structure of a vehicle. Chassis is the integral part of the vehicle it bears the entire load of the vehicle including its self-weight. A weight of chassis is one of the major influencing factors & it must be strong enough to resist shocks, twist, vibrations and stresses [1]. In designing of chassis frame maximum stress and maximum deflections are the important factors. Static analysis of chassis is carried out by finite element method and we obtain the results like stress & deformation. The most suitable method for analysis is the finite element method [2]. A three-dimensional chassis model is created in Creo 5.0 imposed in ANSYS 18.2. Finite element analysis truck chassis was carried out using ANSYS & its static behavior was studied taking 3 different types of materials like Steel, Aluminum alloy, Carbon steels

23-44

Authors: Yasin K. Salman & Hussam Fiesal Abed Hmood

The step height effect of radially inward expanded air flow stream on the heat transfer process in a concentric circular annular passage is studied experimentally. The air flow separation, reattachment and redevelopment took place in the test section which its inner tube subjected to a constant heat flux boundary condition. The experimental apparatus comprised of concentric tubes to form an annular passage with a sudden enlargement in the passage cross-section created by increasing the outer tube diameter of the annular inner tube at the entrance section prior to the test section. The inner tube of the test section was made of aluminium having 25 mm outside diameter and 350 mm heated lengths, which was subjected to a constant wall heat flux boundary condition.The investigation was performed to cover a Re range of 3000 – 11000, inner tube heat flux varied from 800 W/m2 to 1750 W/m2 and the enhancement of step heights were S = 0 ( without step), 6.5 mm, 12.5 mm, and 18.5 mm which refer to Di /d = 1, 1.5, 2 and 2.5, respectively. Results reveal for all cases, that the local heat transfer coefficient increased against increasing the heat flux and/or Re. The step height has an eminent effect on heat transfer in the separation region which decreases with the raise of the step height. The passage without step (S=0) results were correlated and compared with the availableturbulentforced convectionentry length correlations for same geometry and boundary conditions. The step height effects show, for S= 6.5 mm a 25% on the average improvement in heat transfer for a full Reynolds number tested while for another two step heights the results show a limited improvement in low Reynolds number to a 16.5% reduction in heat transfer due to separation zone effect. The velocity profiles demonstrate that the position of reattached point behind the step increases with the rise of step height.The present results show a good agreement with the available previous works and have followed similar trends.

15-26

Authors: Bangarappa. L& Thammaiah Gowda

The data presented shows a dependence of natural frequencies, peak amplitudes and damping levels of four audio vibration modes in the different frequency range up to 1000 Hz on crack types and crack locations. Data from defective single crystalline wafers exhibit lower natural frequencies, higher damping levels, and lower peak amplitudes. From the results suggest an impact test method may be very useful for solar cell crack detection and quality control in the photovoltaic industry. The aim is to experimentally conduct and detect cracks from vibration measurements introduced by striking the single silicon wafer with an impact hammer. Such a method would reduce costs in the production of solar cells or photovoltaic industry