Turbine Inlet Flows Downstream of a Dual Piloted Swirl Flame
Abstract
Among the most challenging aspects of modern gas turbine engine design, particularly with aviation applications, is the balance between the extreme conditions necessary to achieve highly efficient combustion that minimizes emissions, and the structural and material limitations of available manufacturing techniques. Due to the difficulty of these problems, computational fluid dynamics and other model-based design tools are often utilized during the development process to better predict how an engine will perform without the high expense of repeated hardware testing. However, these models have limitations in that they often require strong assumptions to reduce the computational expense, and thereby rely on tuning based on empirical data. High-fidelity measurements are needed to not only validate these model outcomes, but also to establish correct boundary conditions. In this work, we report our progress on the development and demonstration of advanced, non-intrusive laser diagnostics in conjunction with traditional instrumentation in a high pressure combustion test rig. Two dimensional flow field velocity measurements have been performed in a region downstream of the combustion zone in a premixed, swirl stabilized combustor. Point velocity measurements were acquired at a series of spatial locations using Laser Doppler Velocimetry (two components). These measurements were succeeded by a series of planer field measurements, encompassing the same spatial locations, using two dimensional Particle Image Velocimetry. The measurements were performed at two different experimental conditions, at combustor inlet temperatures 100°F apart to examine the temperature dependency of the flow field. The following work evaluates the outcomes of these measurements and reveals that a lower combustor inlet temperature produces a central core deficit significantly less drastic than the higher temperature case. Accompanying this reduced-strength deficit are greater amount of velocity fluctuations. An analysis in the frequency domain attempts to identify the driving mechanisms behind the fluctuations.
Degree
M.S.A.A.
Advisors
Slabaugh, Purdue University.
Subject Area
Aerospace engineering
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