In this study, flow fields around idealized conical waveriders as well as aerodynamic characteristics are examined experimentally in TMIT hypersonic wind tunnel. Flow fields are observed with a schlieren system and aerodynamic forces are measured by a three-component balance. From the force measurement, the L/D ratio of on-design-/off-design- waveriders are found. The result shows that for waveriders with fins, value of L/D ratio drops as the decrease of angle of attack rapidly, whereas for a half cone, not so suddenly. Moreover from schliren photographs, shock shapes of attach/dettach condition are examined. The these photographs show that for planform-, small- and on designfins, shock shapes are conical, and for a large-fin, the shape is not conical.
The supersonic flow and mixing fields with a perpendicular air injection from a finite length slit are investigated. Two slit angle cases of 90 and 45 degrees are examined. The experiments and the calculations are performed. In the calculations, the mixing fields can be discussed because the main flow air is treated with the equation different from the one of the injected air. The numerical results agree well with the experimental ones qualitatively and quantitatively. The results of the 90 degrees slit angle case show that the flow and mixing field is three-dimensional because of the existence of the slit ends, even if the slit is fairly long. As regards the 45 degrees case, the fields are more three-dimensional and complicated. All the results show that a part of the main flow which gets into downstream side of the slit influences on the mixing in the higher order than the vortex in the vicinity of the slit ends.
The broadband noise of low-speed axial-flow fans was extensively discussed from both aspects of experiment and analysis. It was observed that the sound pressure level depended strongly on the diffusion factor D over a wide range of fan operations up to near surge point. For the moderate and heavy aerodynamically loaded blades, the emitted sound level was proportional to D6W6, where W is the blade relative velocity.
This paper presents the modeling of CELSS (Controlled Ecological Life Support System) and the evaluation of its control method. The computer model of the CELSS, which revitalizes water and air by physico-chemical process, is developed and its system dynamics is analyzed. Then, we propose a control method for the CELSS by estimating control inputs based on fuzzy linear programming method. The factors to be controlled, or the stocks of water, oxygen, and so on, are quantitatively indicated in terms of membership function, and the distribution of power into the system is determined so that the minimum values of the stocks reach maximum. Once the power is distributed in the system properly, the values of control inputs are determined. The applicability of this control method is evaluated by investigating the influence of the disturbances due to human activities and other factors.
In the previous paper, we developed and analyzed the computer simulation model of the CELSS. We also proposed and evaluated its control method which defines control inputs based on fuzzy linear programming. In order to develop more reliable system, the, detailed analysis of the system components is required. In this paper, we developed three different systems; (1) the system with a fuel cell, (2) the system without a tank of hygiene water, and (3) the system without an electrolysis tank. From the result of dynamic computer simulation, the behavior of these systems was evaluated in comparison with the system developed in the previous paper.