The S-band inter-satellite communication system for Japan's Engineering Test Satellite-VI (ETS-VI) to be launched in 1992, is presented. The S-band inter-satellite communication equipment system (SIC) provides a multibeam array antenna with 19 microstrip antenna elements, which is being developed in Japan for an experiment S-band intersatellite data relay and tracking satellite system. The SIC has the compatibility with NASA's S-band multiple access system in Tracking and Data Relay Satellite System (TDRSS) to access to user satellite in TDRSS. The SIC provides an on-board microprocessor for directing the beams to any desired user satellite and on-board beamforming networks. This paper describes performances of the SIC and the experimental S-band inter-satellite communication system using the SIC.
In this paper we show a numerical procedure for computing the incompressible viscous flow about an airfoil with a slat and a flap. The full Navier-Stokes equations are discretized in the curvilinear coordinates, using the cell method. The generalized Quick method is incorporated to suppress the instability from the convective terms at higher Reynolds numbers. The Multi-Domain technique, which divides the whole computational domain into several subdomains, is used to calculate this flow problem with a complicated geometry. Each solution is connected at the domain boundary by a versatile interpolation method. This procedure has been applied to calculate the flow about a NACA4412 airfoil at high Reynolds number for various attack angles, which resulted in a good agreement with experiment. Furthermore, the flows around an airfoil with a slat and a flap were successfully calculated. The flow patterns around the airfoil and inside the narrow slat and flap gap, and the effect of a jet through the gap are made clear. These results also show reasonable aerodynamic coefficients up to the stall region for two cases of flap deflection angle: 0°and 40°.
Pursuit-evasion maneuvers of two aircrafts are formulated and solved numerically as differential games. The formulation uses nonlinear equations of motion and inequality constraints are posed on thrust, angle of attack and load factor. Modified Miele et al.'s algorism is used to obtain min-max solution. Numerical results show typical maneuvers of two aircrafts in persuit-evasion games.
The transonic potential flows in the throat region of two-dimensional and axi-symmetric nozzles were calculated using a biquadratic expression for the velocity potential in case of R/h=3, 4 and 5, where R is the radius of throat wall and h is half width of throat. The solutions obtained may be available to compare with various numerical solutions. And the effect of radius of curvature of the wall were calculated. Moreover, the flow was visiualized by the Schlieren technique.
In the mobile satellite communications system, an adaption of small and economical earth terminals, by realizing the large satellite EIRP is particular important. In order to satisfy this requirement, a large antenna and high power output transponders are necessary, simultaneously, reducing the mass of communications equipments in the satellite is required. In this paper, the relations between the total mass of communications equipments and each characteristics of transponder and antenna in the satellite are derived. As a result, the optimum transponder output power, antenna diameter and beam number which give the large satellite EIRP with minimum mass of communications equipments are shown.