The aerodynamic interaction flow field between a delta wing and a hemisphere-cylinder modeling TSTO (Two Stage To Orbit) in hypersonic flow has been investigated. The paint method for visualization has been improved in order to perform temperature distribution measurements by the Temperature Sensitive Paint (TSP) method, where pressure sensitivity has been reduced by recoating a transparent acrylic paint. The flow field is made complicated by both shock/shock interaction and shock/boundary layer interaction. On the hemisphere-cylinder, the maximum heat flux becomes about 2.7 times as large as the stagnation heat flux in the case of a hemisphere-cylinder alone. On the other hand, the same amount of heat flux as that stagnation value is produced on the delta wing located below the tip of the hemisphere-cylinder.
A single-engine turbo-prop aircraft capable of carrying about ten passengers is used both for business and for private purposes. This paper aims to discuss the aircraft configurations that are suitable for these two different purposes. The aircraft conceptual design method that incorporates a boundary element method is applied here to design the aircrafts of interest. The results suggested that the minimum direct operating cost aircraft suitable for the business purpose has smaller wing area, lighter fuel weight and higher wing aspect ratio as compared with the minimum take-off weight aircraft aimed for the private purpose.
Modern day helicopters are frequently required to operate close to non-uniform ground surfaces. During operations above a moving ship deck, it can be foreseen that the hovering performance of the rotor has very different behavior compared with the cases of hovering above stationary flat ground plane. In this report, the hovering performance of the rotor above the moving ground in full ground effect is experimentally studied in order to provide qualified database for the validation of analytical study on dynamic ground effect. The moving ground is simulated by means of harmonic rolling and heaving motions of ground effect plate with variable amplitude and frequency. The thrust, torque and blade flap angle of the rotor were measured at rotor height from 0.4 to 1.5. It is shown that motion types of the ground and the amplitude and frequency of the moving ground have important effects on the variable loads in and out of the rotor disk in dynamic ground effect.
In 5-axis balance calibration test except rolling moment of 60cmMSBS, the relation between coil currents and magnetic force was able to be obtained by varying current in each coil and measuring the force with an industry manufactured balance with very small influence of magnetic field. Consequently, there is a relation between an appropriate coil current combination and the force which can be decided uniquely, and it concludes that 60cmMSBS works as a 5-axis balance. The errors of drag, side force, lift, pitching and yawing moments are below 1.6, 1.4, 4.1, 0.8, and 0.9% in the tested range, respectively. These figures are the error evaluation limits by accuracy of the balance, and a possibility of being still higher accuracy remains. All the errors shown are due to a loop-like hysteresis. If the balance calibration range narrows, it is effective in suppressing nonlinearity and a loop-like hysteresis, and making the balance error smaller.
The theorems of Castigliano are revisited. Based on the Galerkin equation for the equilibrium equations, we obtain the generalized principle of virtual work with the virtual displacements on the displacement boundary, from which we get the theorem of minimum generalized potential energy for the linearly elastic material. From the minimum theorem, we have the generalized first theorem of Castigliano which can be reduced to the conventional first theorem of Castigliano for the case where body forces are absent. Then, based on the Galerkin equation for the strain-displacement relations, we obtain the generalized principle of complementary virtual work with the virtual stresses on the stress boundary, from which we get the theorem of minimum generalized complementary energy. From the minimum theorem, we have the generalized second theorem of Castigliano which can be reduced to the conventional second theorem of Castigliano for the case where the displacement boundaries are fixed. The obtained theorems are applied to analyze the extention of bars, demonstrating the effectiveness of the generalized theorems of Castigliano as well as that of the minimum theorems of generalized potential energy and the generalized complementary energy.
An ESD (Electro-Static Discharge) test was carried out on solar array for Wideband InterNetworking engineering test and Demonstration Satellite (WINDS). An electron beam was used to simulate the inverted potential gradient conditions. The sustained arc was not observed for test coupons with Room Temperature Vulcanization (RTV) Si grouting at the inter-string gap and thicker RTV layer between cells and Kapton sheet. Arc pulses short-circuited the PN junction of triple-junction cells once the arcs occurred at the cell edges. Effects of exposing bus bars to space without RTV coating was also investigated. There was no detrimental effect associated with the exposed bus bars.