Study of Aircraft with Hybrid Laminar Flow Control Based on Exergy Analysis

摘要

Laminar flow control is a technology that can improve fuel consumption by reducing friction drag acting on an aircraft surface. When a laminar flow control system is applied to an aircraft, two aspects of benefit and penalty have to be considered, that is the benefit of drag reduction and the penalty of weight increase due to the system installation. However, conventional aircraft conceptual design methods independently consider these different properties. Thus, there are difficulties in explicitly comprehending the influences of these parameters on design results. In this paper, exergy, which is the maximum effective work of a system, is considered. By using exergy, this paper aims to discuss the weight, energy and aerodynamic characteristics of an aircraft collectively. In particular, aircraft with a hybrid laminar control (HLFC) system are focused on in this paper and a quantitative evaluation of the benefits and penalties of the HLFC system is considered. For this purpose, a multi objective optimization study of aircraft with HLFC was conducted using the concept of exergy. Three different classes of aircraft, that is, B737, B767 and B777 class aircraft were considered. The results indicated that for larger class aircraft (B777 class) with HLFC, the reduction of exergy destruction is dominantly observed compared with smaller class aircraft (B737 class). Even on a short range flight, benefits of the HLFC are obtained for larger class aircraft, but there are few benefits for smaller class aircraft.