Approximate solutions of range for constant altitude – constant high subsonic speed flight of transport aircraft

Cavcar, Aydan; Cavcar, Mustafa

doi:10.1016/j.ast.2004.04.002

Cited by 24 publications

(23 citation statements)

References 6 publications

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“…As originally reported by Hilton (1952), Lock suggested an empirical functional relationship for the wave drag in the airspeed range above critical Mach number (M §M CR ), i.e., Cavcar & Cavcar, 2004;Filippone, 2012;Malone & Mason, 1995;Mason, 2002). Using the above wave drag relationship and combining it with the definition of M DD, it is calculated that M DD~MCR z0:1077.…”

Section: Airplane Drag and Power Requiredmentioning

confidence: 95%

“…Such complex CFD approach is cumbersome to implement in conceptual designs and the first drag estimates phase. However, according to Cavcar and Cavcar (2004), Malone and Mason (1995), Mason (2002), and Filippone (2012), the M DD as a function of lift coefficient and for given wing/airfoil geometry can be reasonably well estimated with:…”

Section: Airplane Drag and Power Requiredmentioning

confidence: 99%

“…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). Sometimes another criterion is used for the M DD definition, and that is a Mach number at which compressibility wave drag increased by 0.002 (Cavcar & Cavcar, 2004).…”

Section: Airplane Drag and Power Requiredmentioning

confidence: 99%

“…Raymer (2004) derived an approximate method to derive loiter (endurance) time from the Bréguet range equation. Cavcar and Cavcar (2004) deliver approximate cruise range solutions for the constantaltitude and constant-high-subsonic cruise speeds of a transport category aircraft with cambered wing designs. The authors also used Mach-dependent specific fuel consumption (SFC), which is different from the one introduced here.…”

Section: Literature Reviewmentioning

confidence: 99%

“…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). Sometimes another criterion is used for the M DD definition, and that is a Mach number at which compressibility wave drag increased by 0.002 (Cavcar & Cavcar, 2004). While some wave drag exists between M CR and M DD, it will be for the most part neglected in this study, and M DD will be taken as the maximum operating airspeed even when the powerplants are capable of accelerating an aircraft to higher M-speeds.…”

Section: Airplane Drag and Power Requiredmentioning

confidence: 99%

See 4 more Smart Citations

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

Daidzic¹

2016

Journal of Aviation Technology and Engineering

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Conventional Mach-independent subsonic drag polar does not replicate the real airplane drag characteristics exactly and especially not in the drag-divergence region due to shock-induced transonic wave drag. High-bypass turbofan thrust is a complicated function of many parameters that eludes accurate predictions for the entire operating envelope and must be experimentally verified. Fuel laws are also complicated functions of many parameters which make optimization and economic analysis difficult and uncertain in the conceptual design phase. Nevertheless, mathematical models and predictions have its important place in aircraft development, design, and optimization. In this work, airspeed-dependent turbofan thrust and the new fuel-law model were used in combination with an airplane polynomial drag model to estimate important performance speeds. Except for the airframe-only dependent control airspeeds, all performance speeds are airframepowerplant dependent. In all analytical considerations one ends up with polynomials of the 4 th order that have no closed-form solutions. A real positive-root seeking numerical procedure based on the family of Newton-Raphson methods was used to extract performance airspeeds for variable in-flight weights and altitudes in the ISA troposphere. Extensive testing of the accuracy and convergence of the Newton-Raphson nonlinear equation solvers was conducted before performance speed calculations. A fictitious long-range wide-body transport-category airplane was modeled in combination with a pair of high-bypass and ultra-high bypass ratio flat-rated turbofans. Procedure employed here can be easily extended to cases when fitted, measured drag and thrust data is given in arbitrary polynomial forms. Sensitivity analysis is performed on minimum-drag airspeed and maximum aerodynamic efficiency. Transonic wave drag considerations are introduced. About the AuthorsDr. Nihad E. Daidzic is president of AAR Aerospace Consulting, LLC. He is also a full professor of aviation, adjunct professor of mechanical engineering, and research graduate faculty at Minnesota State University. He has a PhD in fluid mechanics and ScD in mechanical engineering. He was formerly a staff scientist at the National Center for Microgravity Research and the National Center for Space Exploration and Research at NASA Glenn Research Center in Cleveland, OH. He has also held various faculty appointments at Vanderbilt University, University of Kansas, and Kent State University. His current research interest is in theoretical, experimental, and computational fluid dynamics; micro-and nano-fluidics; aircraft stability, control, and performance; and mechanics of flight, piloting techniques, and aerospace propulsion. Dr. Daidzic is ATP and ''Gold Seal'' CFII/MEI/CFIG certified with flight experience in airplanes, helicopters, and gliders.

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Section: Airplane Drag and Power Requiredmentioning

confidence: 95%