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If an airplane crashes, the recorded radar data can be used to reconstruct a time history of the airplane’s calibrated airspeed, load factor, excess thrust, bank angle, etc. Previous work on this problem has used a rectilinear approach to the calculations involved in the flight parameter reconstruction. The rectilinear approach gives excellent results for relatively straight flight; however, it routinely underestimates the airspeed and the bank angle when the airplane is maneuvering. In the present study, the authors present a curvilinear approach to flight parameter reconstruction that addresses this shortcoming. The analysis presented shows that the curvilinear approach is a far superior tool than the rectilinear approach for the reconstruction of maneuvering flight including steep turns and high-speed spirals.

Using a panel method, the flow over various residential roof designs was analyzed and an estimate of the pressure distribution across the roof was determined. This pressure distribution was analyzed to determine the potential for flow reversal through the ventilating system of a gas-fired appliance. It was found that, for several roof configurations and wind speeds, relatively low pressures could exist on the roof of a residence. In addition, some appliance venting configurations, combined with the local pressure distribution, will impose pressures on the appliance inlet and exhaust that can result in a reversal of the normal flow direction. If the flow is reversed and the appliance is installed in a closed area like an airtight closet, hot exhaust gasses will be allowed to enter areas not designed for high temperatures and a fire can result.

Optimal control theory has been used in the aerospace industry for many years. It has been applied to a wide variety of problems ranging from orbit transfer routes to missile tracking strategies. This paper discusses the application of optimal control theory to several residential heating and cooling systems. The optimal control strategy is determined and then approximations to that optimal strategy are presented. These approximate strategies are much easier to implement than the true optimal strategies. The performance of the approximate strategies relative to the optimal strategies is presented and shown to be an effective means for reducing utility peak demand.