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Integrating the seemingly divergent objectives of aircraft seat configuration is a difficult task. Aircraft manufacturers look to design seats to maximize customer satisfaction and in-flight safety, but these objectives can conflict with the profit motive of airline companies. In order to boost revenue by increasing the number of passengers per aircraft, airline companies may increase seat height and decrease seat pitch. This results in disaccommodation of a greater percentage of the passenger population and is a reason for rising customer dissatisfaction. This paper describes an effort to bridge this gap by incorporating digital human models, layout optimization, and a profit-maximizing constraint into the aircraft seat design problem. A simplified aircraft seat design experiment is conceptualized and its results are extrapolated to an airline passenger population.

In this paper a model of a three-phase inverter drive will be presented that is suitable for inclusion in a DC distribution system analysis. It will be shown that the drive can be accurately modeled on the electrical side by a capacitor, representing the bus capacitance of the inverter, in parallel with a current source. The current source consists of a DC component, corresponding to net power flow to and from the flywheel, plus high-frequency current harmonics generated by the operation of the switch-mode inverter. Closed-form expressions for the current harmonics can be derived by analyzing the AC currents in the electric machine and the switch-mode nature of the inverter, including the “dead-time” effect, and will be presented in the paper. Comparisons between edge-based and center-based pulse-width operation suggest that center-based PWM produces less harmonic content. It is shown that “dead-time” can have a significant effect on the harmonic content.

It is well known that, for propeller-driven airplanes, maximum fuel economy occurs at maximum L/D ratio. It has been shown that, while the speed for maximum L/D yields the least fuel consumed per unit of distance, there is also a speed for the least fuel per unit of velocity, essentially, the best compromise between speed and fuel economy. This paper presents a simple method to predict this optimum airspeed in terms of calibrated airspeed. In this form, it is only a function of gross weight and could easily be made available in operating handbooks in the form of two-dimensional charts. It is shown that the optimum airspeeds for the range of normal operating gross weights requires fairly normal cruise power settings. The study further describes a simple, straightforward method of arriving at the relationship of cruise optimum airspeed in terms of maximum L/D speed.