Aerodynamics and Propulsion principles Coursework

Aerodynamics and Propulsion principles - Coursework Example To understand the operation of a turbofan, first we need to look into its construction and the function of individual components. Figure 1 describes the arrangement of the components of a turbofan and indicates the direction of normal air flow in the engine. All the 5 components: intake, compressor, combustion chamber, turbine and the exhaust nozzle have their unique role to play in the working of a turbofan and contribute in providing the necessary thermodynamic and aerodynamic requirements of the overall system. By understanding the individual function of these components, we can determine the performance measures and the complexities that have to be considered in the design of a turbo fan. Before we proceed to the operation of a gas turbine, we will describe the aerodynamic role of individual parts.In this section, we will describe the aerodynamic behavior of the engine components that were mentioned in section 1 in the same order as the air encounters them in a turbofan. Intake g uides the air from the atmosphere to the fan of the engine and assists the engine by increasing the pressure before the air is sucked in by the engine (Gordon). It has an aerodynamic design to minimize the drag and is basically a nozzle with increasing cross section (Jet Propulsion) that results in a higher pressure at the fan. Moreover, its front should not generate any turbulence in the flow of air as it can cause severe conditions inside the engine and lift may dangerously drop. Intake has to accommodate both the bypass and engine streams of air so that no considerable pressure gradients result at the face of the fan. For faulty conditions, intake may have to provide a larger mass of air than normal requirement of an engine and so has to have a reasonable choke limit. 3.2 Fan and Compressor Compressor is the first component of considerable aerodynamic complexity that the air meets in its way to the exhaust. A compressor is made up of several fan-like moving blades called airfoils alternately arranged with the stators are the stationary blades (Figure 2). Figure 2: Axial compressor. (Turbine Engines) The airfoils blow the air ahead and stators decelerate it, thus increasing the pressure with successive sections. There are usually two separate parts of a compressor: the low pressure and the high pressure compressor. This division is necessary because as the pressure increases, the speed of rotating airfoils has to increase. To maintain the air mass flow rate which depends both on the speed of flow and pressure, compressor