Papers by Keyword: Wind Tunnel Test

Abstract: A kind of novel airfoil sail is proposed in this paper based on the research of traditional arc wing sails. The aerodynamic characteristic- the lift coefficient and drag coefficient is numerically calculated with FLUENT 6.0 and the results are verified by wind tunnel test. It is proved that the aerodynamic characteristic of the novel sail is much better than the arc wing sail.

Abstract: Based on the analysis of automobile aerodynamic noise generation mechanisms and the components of interior wind noise, the spectra characteristics and spatial distribution rule of sound level of interior wind noise were investigated at first, then the frequency characteristics and noise level under different wind speeds, different yaw angles in SAWTC full-scale aeroacoustic wind tunnel were studied. The results show that: the interior noise level was nearly symmetric on vehicle left and right side, noise level of outboard ear was normally higher than that of inboard ear. The frequency characteristics under different wind speeds were almost the same, the linear OASPL of interior noise increased at about 4.4th power and A-weighted OASPL at about 5.5th power of wind speed. In addition, the acoustic power increased as yaw angle rose up, and noise level by leeward side was normally higher than that by windward under the same yaw angle.

Abstract: To research the aerodynamic characteristics of minibus, the simplified model is studied with simulation and wind tunnel test. The validated method was adopted in the numerical simulation, the wind tunnel test were carried out in order to validate the results of numerical simulation. The tests include aerodynamic drag measure, filament method, and laser flow visualization. Through the contrasted research the results of simulation and test, the aerodynamic characteristics of minibus was analyzed and the characteristic of field around minibus was discovered. The conclusions provide the theoretical foundation for styling optimization of minibus, which are very helpful to develop new vehicle styling.

Abstract: In this paper, pressure time history on curtain wall of high-rise building are sampled through synchronous multi-spots pressure measurement test in wind tunnel. Peak pressures are calculated by using the method mentioned in this paper for design of curtain wall. Some results and conclusion are useful for design of curtain wall on high-rise building.

Abstract: In this paper, the system and the design philosophy of wheel-spoke cable-membrane structure of Baoan Stadium is introduced firstly. And then the study of wind tunnel test on 1:250 scale model is mainly presented, together with the numerical calculation of the wind dynamic response. Finally, the wind-resistant design of the roof structure based on the results of wind tunnel test and the foreign design codes is generally introduced.

Abstract: This paper takes a Chinese Changjiang River highway bridge as engineering background, and a kind of continuous three-dimensional (vertical, lateral and torsion)controllers which can apply in the large span cable-stayed bridge is presented. The controllers can control vertical, lateral and torsional response of bridge wind-induced vibration at the same time. Through comparative wind tunnel test of the bridge model with and without controllers, some important conclusions are made as follows: when the continuous three-dimensional controllers are installed on the bridge model, its flutter critical wind speed increases significantly (mostly increases 33.36%); Meanwhile, there is a certain degree of reduction in its RMS values of vertical, lateral and torsional angular displacement response.

Abstract: Experimental research on transition and flow separation of laminar airfoil and the influence of transition and flow separation on the performance of laminar airfoil are carried through. The experimental device and instruments used in the research are introduced. It is shown from the experimental results that at certain scope of attack angle, flow transition shifts from 50%c to 30%c on the upper surface of airfoil model along with 1 degree increase of airfoil attack angle; For flow speed of 35m/s and 50m/s with attack angle from 4 degree to 8 degree, flow separation position don’t vary but only separation scope increase; For flow speed of 15m/s laminar flow separation on the upper surface of airfoil take place at attack angle of 4 degree, flow become attaching at attack angle of 6 degree and turbulent flow separation take place at attack angle of 8 degree.

Abstract: Based on the wind tunnel test of a mass culture activity center, the influence of the shape change of the structure with abnormal roofing on the wind loads shape coefficient were studied. The result from the test was compared with the values from the related items in the《load code for the design of building structure》^[1]. Research results shows: the shape coefficient of the abnormal roofing structure is unfavorable to take norms similar structure shape coefficient values, need to measure it through wind tunnel tests.

Abstract: Computational fluid dynamics and wind tunnel test are two main technical means to examine the aerodynamic performance of airfoil and two-dimensional(2-D) configuration. Two dimensional wind tunnel tests use commonly wake flow field measurement to integrate for drag of airfoil or two-dimensional configuration, but the integral formulas are based on certain assumptions and of certain bounds of application. In this paper, based on Navier-Stokes equations numerical simulation and two dimensional wind tunnel testing, the drag measuring technique for high lift configuration in low speed wind tunnel is researched. Navier-Stokes equations is solved for the flow around a multi-element airfoil, the wake flow characteristics behind the multi-element airfoil and the assumptions for conventional drag measuring method are analyzed, then a new more precise drag formula for two dimensional wind tunnel test is put forward; Based on the simulation results of multi-element airfoil flow, it’s aerodynamic performance is obtained respectively by integrating the surface pressure and friction drag, and computing with the information of wake flow according to conventional and newly proposed drag calculation formulas, and the three results are compared to verify the accuracy of the new drag formula; The wind tunnel test is carried out to ascertain the accuracy of the new drag formula. It is shown from the results that in the high-lift case the conventional drag formula with the wake information is of many limitations and must be improved, and the new drag formula presented in this paper is more accurate because of consideration of the wake flow characteristics of airfoil or two-dimensional configuration.

Abstract: Icing on blade surface of the wind turbine set in cold regions is a serious problem. To invest the mechanism of icing and ice accretion on blade surface, wind tunnel tests were carried out on a static straight blade used for the straight-bladed vertical axis wind turbine by using an icing wind tunnel. The icing and ice accretions on blade surface at some typical angles of attack were observed and recorded in a fixed wind speed and steady flow discharge. The mass of ice accretions on the surface of blade were also measured and compared. At the same time, the drag and lift coefficients were tested by a three-component force balance. Based on the test results, the factors affecting the mass and characteristic of ice accretions and the drag and lift coefficients of the straight blade were discussed.