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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.

Self-rewetting fluids, i.e. dilute aqueous alcoholic solutions with unique surface tension behavior, have been proposed as working fluids for terrestrial and space heat pipes. Experiments have been carried out in normal gravity and in low-gravity conditions with tubular heat pipes, thin flat heat pipes for thermal management in electronic devices, and flexible, inflatable and deployable radiator panels for space applications. Self-rewetting heat pipes exhibit, in general, better thermal performances in comparison with water heat pipes. Current developments are focused on self-rewetting brines, studied as candidate potential heat transfer fluids for space applications. Activities are in progress to perform experiments in space with a small technological payload onboard a microsatellite developed by the Italian Space Agency.

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.

An aerodynamic styling evaluation system employed at an early automotive development stage was constructed. The system based on CFD consists of exterior model morphing, computational mesh generation, flow calculation and result analysis, and the process is automatically and successively executed by process automation software. Response surfaces and a parallel coordinates chart output by the system allow users to find a well-balanced exterior form, in terms of aerodynamics and exterior styling, in a wide design space which are often arduous to be obtained by a conventional CAE manner and scale model wind tunnel testing. The system was designed so that 5-parameter study is completed within approximately two days, and consequently, has been widely applied to actual exterior styling development. An application for a hatchback vehicle is also introduced as an actual example.

A multi-objective optimization model using a piston behavior simulation for the prediction of NV, friction and scuffing was created. This model was used to optimize the piston skirt form, helping to enable well-balanced forms to be sought. Optimization calculations, involving extended analyses and numerous design variables, conventionally necessitate long calculation times in order to achieve adequate outcomes. Because of this, in the present project data was converted into functions in order to help enable the complex piston skirt form to be expressed using a small amount of coefficients. Using the limit values for manufacturability and the degree of contribution to the target functions, the scope of design variables was restricted, and the time necessary for the analysis was significantly reduced. This has helped to enable optimal solutions to be determined within a practical time frame.

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.