The effect of adding diffuser by experimental

Abstract

The purpose of this project is to improve the aerodynamics coefficient of Proton Persona by adding diffuser onto it. It is done by determining each of the drag coefficient of the model, by experimental method using Low Speed Wind Tunnel. All the relevant data are collected through the literature reviews from books and journals. First, the basic thing in aerodynamic is studied. Then, the theory of the diffuser need to be understand. Diffuser can work to reduce drag and increase downforce of the vehicle. There are things that need to be concerned when studies aerodynamics. They were air flow and vehicle shape which we regard as aerodynamics factor that will determine aerodynamic of the vehicle. Fundamental of air flow and vehicle shape is reviewed includes the relationship between air speed with pressure, the boundary layer, Reynolds number, drag, lift drag and shape optimization. Wind tunnel is also closely studied before the experiment is conduct. In methodology, model specification and experiment procedure is explained, together with considered assumptions. Five selected speed were been tasted during the experiment to determine the Drag Coefficient (CD) value. The relevant graphs are then plotted and discussed. Then, the diffuser angle with the minimum CD will be chosen to calculate the drag reduction percentage.