The energy density per pulse, the peak power density and its duration from a Blumlein-type nitrogen laser have been theoretically studied. Both the rate equations based on the saturation approximation and the circuit equations are solved by means of a numerical analysis by the Runge-Kutta method. Calculations are carried out over a variety of physical and circuit parameters such as the gas pressure in the laser tube, the electrode separation, the applied voltage, the capacitances of storage side and spark-gap side, the residual inductances of laser tube side and spark-gap side, and the spark-gap resistance. The relations between output characteristics and individual parameters are illustrated. From these results some considerations in the optimum operation or design are discussed.
Experiments on low speed flows around multi-airfoils were carried out to confirm the numerical method suggested by the same author at the Annual Meeting of the Japan Society for Aeronautical and Space Science, April, 1969. An airfoil model with double slotted flaps and another model with leading slat and slotted flap were tested in the NAL Smoke Wind Tunnel. The tests were carried out under the following conditions: the velocity range from 3.0 to 6.0m/s, the Reynolds number from 0.4 × 105 to 1.0 × 105 and the system angle of attack from 6° to 15°. Stream lines were obtained by taking a photograph of loci of white smoke, and pressure distributions were obtained by measuring the static pressure at holes of the airfoil surface. It has become clear that the numerical results can estimate roughly the experimental results.