The first stage of droplet collection in a droplet collector of the Liquid Droplet Radiator is collisions of droplet streams with a liquid film formed in an inner surface of the collector. When the droplet streams are absorbed in this liquid film, no splashes should be formed to achieve high collection efficiency. As specifications of a droplet collector, a miscapture rate of incoming droplets is required to be less than 10^-6. The collisions and the splashing phenomena of incoming droplets with a liquid film was observed by using a magnifying CCD camera with synchronized irradiation by a laser diode. When the uniform droplet stream is produced where the droplet diameter is less than 300mm, and the droplet speed less than 20m/s, no splash is observed.

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The LE-7 engine which will be used as the first stage main engine for the H-II rocket has been under development in Japan. This engine has a lot of welded joints, but various troubles have occurred at those joints. Therefore, tensile properties of Inconel-718 test specimens with a welded joint were investigated at various temperatures in high pressure hydrogen and helium environments in order to study fundamental characteristics of the welded joints. And by using those results, the relation between tensile properties and micro-structures was examined. It was found of the welded joint that the ductility was less than that of the parent metal and that the deterioration of ductility was due to the dendrite structure of Ni₃Nb phase.

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Some commercial jet liners are equipped with Aircraft Integrated Data System. The digital flight recorded data are obtained on the request of the pilot in command. Using the data, vertical wind can be estimated. Two method are shown. One uses horizontal and vertical acceleration and fuel flow. The other uses pich angle and angle of attack using vertical equation of motion.

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The expansion of two-dimensional flow due to the multiple gauzes in a free stream was analytically and experimentally studied. The flow profiles were calculated by Taylor's revised source flow model, and the relationship between the resistance of the gauzes and the source-strength correction was discussed. The expansion profiles were also observed with a low-speed smoke wind-tunnel. Concequently, good agreement between the calculated and observed profiles was obtained for various different low resistance gauzes. Futhermore, two-dimensional wide-angle diffuser models with three gauzes were designed by the source flow model, and flow observations and velocity measurements were also made on the diffusers.

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This paper mainly discusses about the physical relations between flight data, analysis methods and aerodynamic characteristics. This 5th report forcuses the effects of gusts and time lags in flight data on the estimations, which use the equation error method and the perpendicular error method proposed by the 4th report. Gusts are essentially profitable for aerodynamic derivative estimations. If air data are precisely measured in strong gusts, multicollinearities diminish so that all aerodynamic derivatives are more exactly estimated. The time lag of a certain variable generates the virtual aerodynamic force in proportion to the time-derivative of its variable, and the estimation results include this virtual force component. As gusts are airfiows moving along an airplane, the effects of their time lags on airdata and regression models should be noted.

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In order to avoid the potential risk of damage caused by the hammering during the assembling operation of Marman Clamp, an alternative method to unify the tension in the Marman Clamp bands is proposed. The method is to eliminate the effects of friction, which is the cause of the tension nonuniformity, by slightly sliding the clamp block when the band pre-tension is set. In order to confirm the effectiveness of the method, the Marman Clamp of an upper-stage inter-stage joint of Mu-3SII satellite launcher was assembled with and without the application of the present method, and the stain distribution was measured. The comparison of the data clearly indicated the effectiveness of the proposed method.

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