Assembly fit-up issue: investigation of a first stage high pressure gas turbine rotor

Abstract

A Gas Turbine engine generates mechanical energy from a combustible fuel. This mechanical energy could be converted into electrical power by means of a rotating shaft as opposed to the pressurized thrust generated on a gas turbine jet engine. Within the different variations of gas turbine engines, the Turbofan is the one configuration that is most commonly used across the commercial and military aviation industry because it provides high thrust and good fuel efficiency. These characteristics have been made possible in part by the development of new materials that are capable of sustaining higher temperatures, which is more evident on the hot section of the engine: the turbine. A gas turbine engine can be broken down onto five main modules: a) inlet/fan, b) compressor (high pressure and/or low pressure), c) combustor chamber, d) turbine (high pressure and/or low pressure), and e) outlet/nozzle. This is shown on Figure 1 [1]. This article will focus on the highpressure turbine (HPT) module of a Turbofan engine, more specifically, the assembly between a high-pressure turbine Disk and Blades. The blades are installed into a disk as shown on figure 2. These blades incorporate a dovetail design with a total of 4 pressure faces. Pressure faces are called those surfaces that transition tangent from the adjacent radii. The pressure faces on the blades will load against parallel surfaces on the disk during engine operation to distribute loads due to the centrifugal force. The intent of this Disk and Blade sub-assembly is to extract energy coming from the burner. Key Terms – Fit-up, Blades, Disk, High Pressure Turbine.