fighter aircraft
6.The engine hatchway noise level of the main types of fighter aircraft in our country ranged from 117 to 130 dB(A), while the maximum engine hatchway noise of J-8D exceeded 140 dB(A). This is far beyond stipulate criteria for protection of hearing home and aboard, that is the noise should not exceed 115 dB(A) for naked ear noise exposure.
7.Compared with a delta wing aircraft, the double-delta wing configuration has better aerodynamic performance at high angles of attack.An operational analysis was introduced as a method for evaluating training effectiveness of trainer aircraft.Approaches to the engineering estimation of aerodynamic characteristics for aircraft with a double-delta wing configuration were studied, and the procedures for determining aircraft performance indices formulated.Taking training effectiveness as the objective function and geometric parameters of the wing platform as design variables, through a numerical multivariate optimization arithmetic, the conceptual design optimization for a certain fighter trainer aircraft with double-delta wing configuration was carried out under the constraints of tactical and technical requirements and interrelated geometry.Agreement of a calculation example with engineering practice indicates that the optimal design has higher training effectiveness than the baseline design, and in addition, improves the structural force-bearing conditions.
