翻訳と辞書 Words near each other ・ Zero-energy building ・ Zero-energy universe ・ Zero-Force Evolutionary Law ・ Zero-forcing precoding ・ Zero-fuel weight ・ Zero-G (disambiguation) ・ Zero-G Ltd ・ Zero-hour contract ・ Zero-inflated model ・ Zero-intelligence trader ・ Zero-K ・ Zero-knowledge password proof ・ Zero-knowledge proof ・ Zero-length launch ・ Zero-level elevation ・ Zero-lift drag coefficient ・ Zero-load ・ Zero-marking in English ・ Zero-marking language ・ Zero-mode waveguide ・ Zero-ohm link ・ Zero-One United States Heavyweight Championship ・ Zero-order hold ・ Zero-order process (statistics) ・ Zero-phonon line and phonon sideband ・ Zero-player game ・ Zero-point energy ・ Zero-product property ・ Zero-profit condition ・ Zero-propellant maneuver Dictionary Lists mini英和辞書 mini和英辞書 Webster 1913 Latin-English FOLDOC Wikipedia English ウィキペディア

翻訳と辞書　辞書検索 [ 開発暫定版 ] スポンサード リンク Zero-lift drag coefficient ： ウィキペディア英語版 Zero-lift drag coefficient In aerodynamics, the zero-lift drag coefficient $C\_$ is a dimensionless parameter which relates an aircraft's zero-lift drag force to its size, speed, and flying altitude. Mathematically, zero-lift drag coefficient is defined as $C\_\; =\; C\_D\; -\; C\_$, where $C\_D$ is the total drag coefficient for a given power, speed, and altitude, and $C\_$ is the lift-induced drag coefficient at the same conditions. Thus, zero-lift drag coefficient is reflective of parasitic drag which makes it very useful in understanding how "clean" or streamlined an aircraft's aerodynamics are. For example, a Sopwith Camel biplane of World War I which had many wires and bracing struts as well as fixed landing gear, had a zero-lift drag coefficient of approximately 0.0378. Compare a $C\_$ value of 0.0161 for the streamlined P-51 Mustang of World War II〔(【引用サイトリンク】title=Quest for performance: The evolution of modern aircraft. NASA SP-468 )〕 which compares very favorably even with the best modern aircraft. The drag at zero-lift can be more easily conceptualized as the drag area ($f$) which is simply the product of zero-lift drag coefficient and aircraft's wing area ($C\_\; \backslash times\; S$ where $S$ is the wing area). Parasitic drag experienced by an aircraft with a given drag area is approximately equal to the drag of a flat square disk with the same area which is held perpendicular to the direction of flight. The Sopwith Camel has a drag area of , compared to for the P-51. Both aircraft have a similar wing area, again reflecting the Mustang's superior aerodynamics in spite of much larger size.〔 In another comparison with the Camel, a very large but streamlined aircraft such as the Lockheed Constellation has a considerably smaller zero-lift drag coefficient (0.0211 vs. 0.0378) in spite of having a much larger drag area (34.82 ft² vs. 8.73 ft²). Furthermore, an aircraft's maximum speed is proportional to the cube root of the ratio of power to drag area, that is: :$V\_\backslash \; \backslash propto\backslash \; \backslash sqrt()$.〔 ==Estimating zero-lift drag〔== As noted earlier, $C\_\; =\; C\_D\; -\; C\_$. The total drag coefficient can be estimated as: :$C\_D\; =\; \backslash frac\; \backslash rho\_0\; (S\; (1.47V)^3)\}$, where $\backslash eta$ is the propulsive efficiency, P is engine power in horsepower, $\backslash rho\_0$ sea-level air density in slugs/cubic foot, $\backslash sigma$ is the atmospheric density ratio for an altitude other than sea level, S is the aircraft's wing area in square feet, and V is the aircraft's speed in miles per hour. Substituting 0.002378 for $\backslash rho\_0$, the equation is simplified to: :$C\_D\; =\; 1.456\; \backslash times\; 10^5\; (\backslash frac)$. The induced drag coefficient can be estimated as: :$C\_\; =\; \backslash frac$, where $C\_L$ is the lift coefficient, ''A'' is the aspect ratio, and $\backslash epsilon$ is the aircraft's efficiency factor. Substituting for $C\_L$ gives: :$C\_=\backslash frac\; (W/S)^2$, where W/S is the wing loading in lb/ft². 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Zero-lift drag coefficient」の詳細全文を読む スポンサード リンク 翻訳と辞書 : 翻訳のためのインターネットリソース Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.