Aspects of Design and Applications of Wind Tunnels

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1 2003, 3, 19, Aspects of Design and Applications of Wind Tunnels

2 Outline Illustrations of wind tunnels Physical principles of wind tunnel operation Considerations of wind tunnel design Aspects of wind tunnel testing Discussion and concluding remarks

3 Illustrations of Wind Tunnels To provide desirable flow conditions, simulating the realistic flow conditions, for aerodynamic testing and academic studies Physical parameters: flow speed(u) and model size(l), leading to a non-dimensional parameter: Reynolds number Re=UL / υ, υ : kinematic viscosity Low- and high-speed wind tunnels Closed- and open-type wind tunnels (In the following, the presentation will be focused on the aspects of low-speed wind tunnels.)

4 Ames 40 by 80 low-speed wind tunnel

5 Air&Space Museum, Washington D. C.

6 Ames and wind tunnel

8 German-Dutch Wind Tunnels (DNW) DNW LST NWB

9 9.5m 9.5m 3.0m 2.25m 3.255m 2.8m

10 Mach no.: 0.05 to 0.6

11 DERA 8 8 pressurized high speed tunnel M= ;

12 NAL Hypersonic Wind Tunnels M=5,7,9, 11(Φ500mm) M=10 (Φ 1270mm)

15 FluiDyne Transonic Wind Tunnel

16 FluiDyne at Medicine Lake, Minnesota FluiDyne at Medicine Lake, Minnesota

17 LAGG 4m 3m Low Speed Wind Tunnel

19 Physical Principles of Wind Tunnel Operation Conservation of mass Conservation of momentum (fan providing the pressure rise, while pressure loss resulted due to flow motion) Conservation of energy (mechanical energy input by fan, while thermal energy increased due to viscous dissipation)

20 Considerations of Wind Tunnel Design (1/3) Requirements definition: Scope of testing, testing techniques, flow speed range, model size, test section dimensions Resources: Space, budget, manpower, customer, management and support (not only construction, but also long-term operation)

21 Considerations of Wind Tunnel Design (2/3) Technical aspects Wind-tunnel circuit aerodynamic design (pressure drop, flow quality, test section dimensions) Fan selection (pressure rise, volume flow rate, diameter, power consumption) Nozzle and diffuser (length, contour) Guide vanes Heat-exchanger device, and etc.

22 CARDC Wind Tunnel

23 CARDC Wind Tunnel

24 NASA Ames and Wind Tunnel Six 22,500HP Drive Motors

25 Considerations of Wind Tunnel Design (3/3) Conceptual design Design should include all the technical and nontechnical aspects into consideration. The design is an iterative process. Detailed design Mechanical and electrical integration Component, subsystem and system design with software analysis Engineering drawings

26 ABRI 77.9m (a) 4m 3m 36.5m(V max ~30m/s; <1%) (b) 6m 2.6m 21m (V max ~20m/s) 500kW

27 Schematic Drawings of the Tunnel flow Main test section Removable Corner Fan Secondary test section Top view of main test section Top view of secondary test section

29 Project Management Contracts to vendors Coordination between milestone schedules Acceptance tests

30 ABRI ABRI ~ ( ) ( ) ( ) ( ) ( )

31 G

32 Instrumentation Velocity measurement: Pitot tube, hot-wire, PIV (Particle Image Velocimeter) Force measurement: internal- and externaltypes force balances Flow visualization: smoke, tuft, optical, liquid crystal, pressure or temperature sensitive paint, PIV, and etc

33 Laser-Sheet Smoke Wire Flow Visualization

38 Aspects of Wind Tunnel Testing (1/3) Aerospace applications (normally, uniform flow in the test section) Vehicle design and validation: aircraft, missile, and engine configurations; 2-D and 3-D simplified models

39 Wind Tunnel Tests for Aerospace Applications

40 SIMONA, Delft

41 Aviatica-MAI-890 Moscow Aviation Institute (MAI)

42 Russian Moon Lander

43 Aspects of Wind Tunnel Testing (2/3) Automobile design (ground effect, environmental simulation) Measurements of aerodynamic characteristics, noise measurement and reduction, environmental testing, and etc

44 Wind Tunnel Tests for Vehicle Design

45 Aspects of Wind Tunnel Testing (3/3) Building aerodynamic studies (atmospheric boundary layer simulation, turn tables for model testing) Measurement of aerodynamic characteristics, testing of elastic model, dispersion of pollutant, landscape planning Hydrodynamics studies (wind and water wave simulation) Fluid mechanics issues concerning the interaction of wind and water wave interaction

46 Wind Tunnel Tests for Wind Engineering Applications

47 Colorado State University

48 Discussion and Concluding Remarks The role of wind tunnel testing (vs. computational fluid dynamics) From the standpoints of industrial needs and academic interests, in terms of cost, time, and etc Planning a new wind tunnel facility: costs of construction, maintenance, operation, and organization of management Improving the testing techniques continuously (an important and challenging issue for each of the wind tunnel laboratories) *Note that credits accumulate through the experiences gained with the facility.

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<4D6963726F736F667420506F776572506F696E74202D20C8EDBCFEBCDCB9B9CAA6D1D0D0DEBDB2D7F92E707074> 软件架构师研修讲座胡协刚软件架构师 UML/RUP 专家 szjinco@public.szptt.net.cn 中国软件架构师网东软培训中心小故事 : 七人分粥当前软件团队的开发现状和面临的问题软件项目的特点解决之道 : 从瀑布模型到迭代模型解决项