The aerodynamic characteristics of the NAL-16 research rocket which was planned by National Aerospace Laboratory are treated. Especially model wind tunnel test results at the transonic and the supersonic wind tunnel of N. A. L. are shown. Also flight test experiment for stability margin using small NAL-7 rocket is mentioned. The estimation by results of these experiments shows good agreement with flight test result.

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Longitudinal dynamic stability derivatives of firstly a rocket configuration model at Mach nu-mbers from 0.6 to 3.0 and secondly several air-plane configuration models at Mach numbers from 1.5 to 2.25 were measured by the forced-oscilla-tion technique in the transonic and the supersonic wind tunnels at NAL. The static stability deri-vatives measured by dynamic test coincided with those measured by static test. The dynamic sta-bility derivatives, on the other hand, showed themselves being of fairly large values compared with calculated ones.
In addition to the test results, some details of the test equipments and the error analysis for the data reduction system are included. It is shown by this error analysis, that as the output of the balance is decomposed by the resolver into the static and the dynamic derivative components, the latter is very much influenced by the former and that the interference factor can be obtained by the data of wind off condition tests.
Also presented are the damping derivatives in roll, which are measured by another test rig, and which agree precisely with calculated values.

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The aerodynamic characteristics of water rockets are analyzed experimentally by wind tunnel testing. Aerodynamic devices such as vortex generators and dimples are tested and their effectiveness to the flight performance of water rocket is discussed. Attaching vortex generators suppresses the unsteady body fluttering. Dimpling the nose reduces the drag coefficient in high angles of attack. Robust design approach is applied to water rocket design for flight stability and optimum water rocket configuration is determined. Semi-sphere nose is found to be effective for flight stability and it is desirable for the safety of landing point. Stiffed fin attachment is required for fins to work properly as aerodynamic device and it enhances the flight stability of water rockets.

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Vortices generated in a solid rocket motor may cause pressure oscillations, which cause problems such as deteriorated flight performance and payload damage. The building-cube method (BCM) solver is expected to accurately predict such vortex flows using high-order schemes as well as easily manage complex configurations. The aim of this study is to establish an analysis method for the internal flow of a solid rocket motor using the BCM. Computational results obtained in this study are compared with analysis data based on other solvers as well as experimental data for validation. The BCM solver is applied to the validate the converging-diverging verification nozzle, upper jet model, and propellant surface ejection model. Furthermore, it effectively captures the three-dimensional (3D) trailing vortex downstream of the inhibitor and the propellant surface injection flow. In general, the 3D BCM solver accurately reproduces the internal flow field of the solid rocket motor.

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Structural vibration modal response analysis during lift off has been improved in the H I rocket development by considering its launch pad. The original analysis introduced through the technical assistance for the N-I and N-II development had ignored the launch pad. Consequently, the H-I rocket modal analysis has improved the procedure by taking into account of the boundary condition change between the rocket and its launch pad during vertical takeoff. This improvement includes the equations to connect the responses on fixed-free boundary conditions to those on free-free boundary conditions at the instant of lift Off. This paper covers:(1)structural vibration analysis techniques of the N-I, N-II, H-I and H-II rocket, (2)rocket vibration models by substructure modal synthesis method, (3)inherent improvement to introduce boundary condition change into modal response analysis at liftoff event, and (4)evaluation of above improvement by comparing an analysis with its flight data.

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The review reported the microgravity experiments performed using space shuttle, drop tower and Chinese recovery satellite. In addition, the experimental plan for microgravity experiment in the International space station was introduced. From the space shuttle experiment, it was found that the space-grown sample with free melt surface was almost spherical and Marangoni convection enhanced the melt mixing. Whereas the melt mixing without free melt surface was controlled by diffusion. Formation of spherical projections on the surface of InGaSb was in-situ observed using a high speed CCD camera in the drop experiment. Microgravity studies on the dissolution and crystallization of In_xGa_1-xSb was carried out having the sandwich combination of GaSb(111)A/InSb/GaSb(111)B using the Chinese recoverable satellite. It was demonstrated clearly that the shape of the solid/liquid interface and composition profiles in the solution was significantly affected by gravity.

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Fulfillment of reusable launch vehicle is essential as it is one of economic and efficient space transportation methods. In this research, the geometry optimization of TSTO flyback booster was performed based on the optimal trajectory result of WIRES of Kyushu Institute of Technology for three objectives: aerodynamics, aerodynamic heating, and structural weight. We assume a hybrid wing body as a 3D geometry of flyback booster. CFD analysis by FaSTAR is performed to evaluate the objective functions; multiobjective optimization is implemented using SPEA2 which is a kind of evolutionary computation. Moreover, data analysis is carried out on the optimization result; we revealed information in the objective space. Consequently, we have understood that there are differences how to raise lift to drag ratio at subsonic and supersonic, hypersonic. It is an efficient way to make nose of fuselage blunt and bottom flat for minimizing maximum temperature on the body surface.

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