DEFINITION:

Turbomachines are systems that consist in an assembly of several components. The components that have an influence on performances are mainly the compressor, the combustor and the turbine and eventually the heat exchanger, if present. The turbomachines performances study concerns either the performance of an elementary component or the overall performance of the machine that depends directly upon the performances of each component that are the data to be introduced in cycles studies to evaluate this overall performance. The efficiency of the system has a direct effect on the production of green house effect carbon dioxide. Experimental measurements remain a major way to evaluate the real performances of a turbojet, at ground or high altitude conditions. Nevertheless numerical simulation, steady and unsteady, becomes more and more reliable and induces a noticeable reduction of development times even if an ultimate final experimental verification is still necessary. Performances of every elementary components, compressors etc …, tend to reach their limits and the quest of a still better performance, particularly to reduce the greenhouse effect by consumption reduction, needs to consider new and more complicated cycles, involving for instance heat exchangers.

(Source: ACARE Domain 301)

SUBDOMAINS:

1. Compressor : pressure ratio, efficiency, resistance to distortion, stall margin, active control, number of stages
2. Turbine : efficiency, cooling, number of stages
3. Combustion : efficiency, stability, ignition, extinction, instabilities,active control, gaseous emissions, soots
4. The complete engine : thrust, specific thrust, weight, dimensions, specific consumption, emission indices, noise
5. Lifetime
6. Maintenance constraints
7. Cost