飞机设计导论第二章.ppt

Introduction to Aircraft Design 隐身技术 Introduction to Aircraft Design Chapter 2 Why Should We Design a New Aircraft? * Introduction to Aircraft Design 第*页 The world has accepted that flying is an extremely efficient means of quickly transporting people, cargo or equipment, and performing a wide range of other activities. All operators need to increase efficiency, cost-effectiveness, environmental compatibility and safety. By modifying design or operation of existing aircraft. But limited by the inherent capabilities of the original design and the cost-effectiveness of modifications. * Introduction to Aircraft Design 第*页 Necessary to consider the initiation of the design of a new aircraft. Aircraft manufacturers are in the business of making profit out of building aircraft. Initiation of new design is to retain or enhance design capabilities. Requirements and aircraft specification must consider the needs of aircraft operators, whether they are airlines or air forces. Two means of deriving requirement specification, market surveys and operators’ specifications. * Introduction to Aircraft Design 第*页 2.1 Market surveys Major aircraft manufacturers employ marketing departments which produce annual reports. Historical data are analyzed and extrapolated. To examine existing and proposed competitors in the market, analyze there strengths and weaknesses. Aeronautical journals and manufacturers’ brochures（介绍、宣传用的小册子）. * Introduction to Aircraft Design 第*页 2.1 Market surveys The final stage in the derivation of the specification is to determine targets of how much to improve certain performance parameters, comfort, or costs, relative to the competition. Payload range envelope: direct operating costs. Too great an improvement may not be achievable and too little may be too small to be attractive. Checked in conceptual design stage and the specification may be modified. * Introduction to Aircraft Design 第*页 2.2 Operator-derived specifications Military aircraft spec