Aircraft from flight test - thrust drag accounting
Service Detail from IHS ESDU
New Data – Aircraft Performance from flight test Part 2: thrust drag accounting
When deriving force and moment coefficients from flight testing, a comprehensive thrust-drag accounting procedure must be observed. Installed thrust depends on airframe external flow effects; aircraft drag depends on engine intake and exhaust flows. The thrust-drag accounting system must clearly define how all propulsion and airframe related forces are accounted.
It is important to have a consistent, and preferably standardised, structure of definitions for the various components of thrust and drag to ensure no components are counted twice and none are missed. The basic requirements of this ‘book-keeping’ system are that it allows engine and airframe performance to be considered separately, that it has clear definitions of interfaces between engine and airframe flows, that it must be unambiguous, and practical for experimental and theoretical studies. To find out more…..