Aircraft Performance

Abstract

This book describes the principles and equations required for evaluating the performance of an aircraft. After introductory chapters on the atmosphere, basic flight theory and drag, the book goes on to consider in detail the estimation of climbing performance, the relevant characteristics of power plants, take-off and landing performance, range and turning performance. There is then a short account of the use of vectored thrust and a final chapter on transonic and supersonic flight. The emphasis is on deriving and applying simple analytical expressions rather than on computations from extensive numerical data, but all the exemplary calculations refer to current types of aircraft and the few necessary data are provided. The greater part of the book refers to subsonic aircraft flying at subcritical speeds, which can be dealt with using relatively simple equations, but it is shown that some of this simplicity can be carried over to transonic and supersonic speeds.

Estimation of Performance Airspeeds for High-Bypass Turbofans Equipped Transport-Category Airplanes

“…Many existing introductory and expert books dealing with the airplane performance in general, and transport-category (T-category) airplanes certified under FAR/EASA certification standard (CS) 25 in particular, use relatively simple functional relationships between, most often, speed-independent trust and conventional Mach-independent subsonic drag polar to obtain performance speeds (Anderson, 1999;Asselin, 1997, Eshelby, 2000Filippone, 2006Filippone, , 2012Hale, 1984;Mair & Birdsall, 1992;McCormick, 1995;Nicolai and Carichner, 2010;Ojha, 1995;Raymer, 1999;Roskam & Lan, 1997;Saarlas, 2007;Shevell, 1989;Torenbeek & Wittenberg, 2009;Vinh, 1993). This is also understandable as the resulting equations are nonlinear and no closed-form solutions exist in most cases.…”

“…Below critical Mach (M CR ) there are no local shocks anywhere on the wing, so there can be no wave drag either, although increasing Mach number is affecting pressure distribution and thus slightly viscous drag even below M CR (Mair and Birdsall, 1992). The modern supercritical airfoils delay the drag rise (divergence) or M DD .…”

“…Compressibility affects the coefficient-of-lift (C L ), which is described simply by the asymptotic PrandtlGlauert rule (correction formula), or similar more advanced correction (Anderson, 1999;Ashley, 1992;Bertin & Cummings 2009). There is also a small rise in zero-lift parasitic C D0 , not associated with the wave drag, from about Mach 0.6 or 0.7 upward until M DD the drag rise becomes significant (Ashley, 1992;Mair & Birdsall, 1992;Vinh, 1993). The onset of significant wave drag rise due to strong normal shocks inducing localized boundary layer separation is typically based on the criterion that LC D =LM ð Þ0:1 at the Mach drag-divergence number M DD (Cavcar & Cavcar, 2004;Filippone, 2012;Mason, 2002;Raymer, 1999;Torenbeek, 1997).…”

“…For such airplane M MO could be 0.86 (just below M DD ). The drag-rise Mach will decrease with higher C L and also with higher airfoil thicknesses (Mair & Birdsall, 1992;Nicolai & Carichner, 2010;Shevell, 1989), and thus result in an earlier drag-divergence and significant influence of wave drag. That will also reduce maximum cruising speed, maximum range, and cruising aerodynamic efficiency (Daidzic, 2014b).…”

“…Characteristics of modern HBPR (high) and UHBPR (ultra-high) BPR (bypass ratio) turbofans are profoundly speed dependent (Anderson, 1999;Hale, 1984;Jaw & Mattingly, 2009;Mair & Birdsall, 1992;Mattingly, 2005;Phillips, 2004). Some functional relationships do exist, but to have faithful analytical descriptions of thrust available for the entire flight envelope of modern engines is almost impossible.…”