A new low-speed wind tunnel constructed in 1969 at Fuji Heavy Ind. Ltd. is now in operation for various testings of aircrafts as well as automobiles and so forth. 2m×2m open jet type test section has capability of providing wind velocities up to 60m/sec. The design philosophy and the details of tunnel characteristics are described in this paper.
This paper presents a description of the new Kawasaki 3.5m low speed wind tunnel in Aircraft Division, Kawasaki Heavy Industries, Ltd. The wind tunnel has two way uses, 3.5m octagonal closed type test section and 2.5m octagonal open type test section. The maximum wind velocity is 35m/s in the former use and 65m/s in the latter, respectively. The conditions of the airflow is satisfactory. The uniformity of the velocity distribution has been ascertained to be within 2.0% in closed and 0.5% in open type, respectively. It is equipped with apparatuses such as pyramidal type six-component external balance, measured data processing systems, etc.
In order to assess the correct ground effects of aircraft with high-lift systems and especially of V/STOL planes in wind tunnel tests, a movingbelt ground rig has been developed for the 6m Low-Speed Wind Tunnel at the National Aerospace Laboratory. The design philosophy, the detail of the construction, and the test results of that rig are reported in this note.
Tests in a transonic wind tunnel at low-super sonic speeds are subjected to the wall interference such as recognized in the measurements of the pressure distribution of cone-cylinder models. It was indicated by several investigators that the wall interference effects could be minimized by selecting the most suitable porosity at each test Mach number. Evaluation tests with cone-cylinder models were conducted in NAL 2m. Transonic Wind Tunnel which was originally equipped with perforated test-section walls of 20% porosity (normal holes). The scope of the tests included the attempts with porosities reduced in several ways: and as the results showed some promising aspects, one of the test-section carts was reconstructed as a cart with walls of variable-and remotely controlled porosity. Described in this note are the preliminary tests, the construction of the new variable-porosity cart with slanted holes of maximum 8% porosity, and results of tests of a cone-cylinder model of 0.35% blockage. The comparison of the behavior of the slanted-hole test-section with that of normalhole one is also attempted.
Descriptions about two dynamic test techniques in a transonic wind tunnel are given together with the obtained results. The first is measurements of dynamic stability derivatives of cones and a delta wing employing the free oscillation method. By use of a refined model driving mechanism and a newly designed damping meter accurate values of dynamic stability derivatives were obtained with increased efficiency. The second is the measurement of surface pressure fluctuations of a two dimensional oscillating airfoil. Very small pressure transducers are installed in the model, which is oscillated in pitch by an electromagnetic shaker, and the corresponding pressure signals are analysed harmonically. From the fundamental component dynamically stable and unstable regions over the model were determined and the integrated stability derivatives were obtained. At the same time relation between the higher harmonics and the mechanism of an unsteady transonic flow was also studied.
This paper outlines the design philosophy, mechanism, and aerodynamic characteristics of the Mitsubishi 60cm Trisonic Wind Tunnel which has been in operation since September, 1968. Main dimensions and functions of the wind tunnel are as follows: Type: intermittent blow-down Test section size: 0.6m square Mach number range: 0.4-4 Reynolds number: more than 2×106 with reference length of 0.1m Pumping time: 1 hour Max. storage tank pressure: 15 atg Calibration test of the wind tunnel includes the following items a part of which is given herein: (1) Effects of the second throat, re-entry slot and re-entry flap in transonic speed range. (2) Mach number distribution in a test section. (3) Flow inclination in a test section. (4) Surface pressure distribution of a conecylinder. (5) Aerodynamic characteristics of AGARDB and-C calibration models. (6) Surface pressure distribution of a two-dimensional wing profile NACA 64 A 010.
The aerodynamic characteristics of the NAL 50cm hypersonic wind tunnel were tested at Mach numbers of 5, 7 and 9 with respect to Mach number and total temperature profiles at the test section, the effect of Reynolds numbes on the free stream Mach number, and boundary layer thickness at the nozzle exit, etc. Force tests of AGARD standard models HB-1 and HB-2 were also performed and the results were compared with those of other tunnels. From these tests, it is expected that the tunnel will be useful for applied and development research on the aerodynamics of hypersonic vehicles.