Authors:
M. Nasir Uddin; Md. Humayun Kabir Bhuiyan, Dr. Golam Mostofa Pages: 7 - 17 Abstract: Due to the rapid development of the Field Artillery Weapon System (AWS) the projectiles play an important role in modern time ammunition and the development of an efficient projectile is very important. The design parameters of a projectile depend on the drag and lift force acting on it. Therefore, a detailed experimental and simulation is required to understand the projectile performance against the wind. In this article, an experimental and numerical investigation of long-range Artillery projectile (Field and Medium) under different wind conditions are carried out. Three different sizes of projectiles are used in this experiment (105, 122, and 130 mm). The experiment is carried out by placing the projectile in front of the wind tunnel. The simulation was done using simulation software packages changing the Angle of Attack (AOA) (30°, 35°, 40°, 45°, and 50°) keeping the wind velocity and geometry the same. The pressure coefficients have been calculated from the measured values of the surface static pressure distribution on the projectile. Later, the drag and lift coefficients are obtained from the measured pressure and a projected area of the projectiles. The wind flow effect on the projectiles is also analyzed by Ansys software. The simulation and experimental results show a similar trend regarding, drag forces and lift forces. The simulation result shows that the size of the projectile is an important factor that is mostly related to the drag and as well as lift forces. PubDate: 2021-01-08 DOI: 10.12691/ajme-9-1-2 Issue No:Vol. 9, No. 1 (2021)

Authors:
Hazim Abed Mohammed Al-Jewaree; Dhia K. Suker Pages: 18 - 23 Abstract: All engineering industries have proven that there is a demand to maintain heat transfer and in many engineering production processes, an increase in the rate of thermal transfer is required.. The solution lies in adding solid bodies made externally from heat-conducting materials called fins, which in turn have been the subject of very large engineering research by changing shapes, lengths, axis, thicknesses, etc., in order to raise the efficiency of performance in heat transfer to avoid industrial problems and accidents. The materials type and surface area have direct affect of the heat transfer rate depends on the types of materials used and the surface area of the fin. One of the most popular choice is the radial annular fin due to the cylindrical primary surface where the performance of the fins is a function of many parameters, namely the heat transfer coefficient, the fin efficiency and the fins’ thermal resistance. In this research work, an experimental study to investigate the effect of fin heat transfer performance characteristics elliptical fin shape at differnt at its major and minor axis ratio (a/b) with different cooling air velocities. As a results, the optimum ratio is found to be for an elliptical shape fins for forced convection. PubDate: 2021-02-05 DOI: 10.12691/ajme-9-1-3 Issue No:Vol. 9, No. 1 (2021)

Authors:
Eugene F. Adiutori
Pages: 1 - 6 Abstract: Conventional engineering science should be abandoned because: Engineering laws that are proportional equations (such as q = hΔT) cannot describe nonlinear phenomena (such as boiling heat transfer). Engineering laws were created by assigning dimensions to numbers, in violation of the conventional view that dimensions must not be assigned to numbers. Contrived parameters (such as heat transfer coefficient) make it impossible to solve nonlinear problems with the variables separated, greatly complicating solutions. All engineering equations are irrational because they attempt to describe how the numerical values and dimensions of parameters are related, when in fact equations can rationally describe only how numerical values are related. In the new engineering science described herein: Engineering laws describe proportional, linear, and nonlinear phenomena. No engineering laws were created by assigning dimensions to numbers. There are no contrived parameters (such as heat transfer coefficient), and therefore nonlinear problems are solved with the variables separated. All engineering equations are rational because they describe only how the numerical values of parameters are related. PubDate: 2020-12-30 DOI: 10.12691/ajme-9-1-1 Issue No:Vol. 9, No. 1 (2020)