ESDU 76034:1976

ESDU 76034 gives a graphical method for use in initial design that relates the thrust of the uninstalled engine during take-off to the static, sea-level thrust. The method was developed for use in estimating field length and climb gradient and correlates computed performance data for engines representative of current design practice; it applies to turbo-jet and turbo-fan engines over a range of ambient conditions. The effects of reheat (for turbo-jets and for turbo-fans with mixed exhaust flow) and of flat rating are taken into account. The thrust data are plotted against freestream Mach number between 0 and 0.4 and engine design specific thrust; for engines for which that parameter is unknown, a graph relates values to by-pass ratio between 0 and 10 and turbine inlet temperature up to 1550 K (or reheat exit temperature as appropriate). The effects of installation losses have to be considered separately and one of these, the effect of intake total pressure loss, is considered in ESDU 77001.