scholarly journals Design of short low speed Göttingen type wind tunnel: CFD simulation

2018 ◽  
Vol 145 ◽  
pp. 03015
Author(s):  
Hardy Weisweiler ◽  
Jasmina Kojouharova ◽  
Roland Dückershoff
Keyword(s):  
Applied Sciences ◽  
Wind Tunnel ◽  
Test Section ◽  
Cfd Simulation ◽  
Test Chamber ◽  
Sectional Area ◽  
Cross Sectional ◽  
Low Speed ◽  
University Of Applied Sciences ◽  
Open Test

The paper is focused on design simulations by the means of commercial software for a low speed circuit wind tunnel with an open test section, recently built at the Department of Mechanical Engineering, Mechatronics and Materials Technology at THM University of Applied Sciences in Friedberg. The proposed wind tunnel has a test section with cross sectional area of 1 X 1 m2 and a length of 1.6 m. The maximum achievable speed is about 50 m/s with empty test section. The simulation had the target to propose and to verify various geometries - test chamber, tunnel contraction, diffuser etc. as well the tunnel corner including the vanes. In addition, the influence of the vanes number and their shape on the ventilator power needed and the flow velocity uniformity as well, have been subjects of the investigation. Also the ventilator type (rotational segment) impact on the flow pattern within the operational area has been scrutinized.

Experimental Investigations inside the Wind Tunnel at the University of Stralsund

2016 ◽  
Vol 831 ◽  
pp. 117-125
Author(s):  
Thomas Panten ◽  
Heiko Meironke
Keyword(s):  
Applied Sciences ◽  
Wind Tunnel ◽  
Particle Image ◽  
Velocity Fields ◽  
Experimental Investigations ◽  
Wake Structure ◽  
Image Velocimetry ◽  
University Of Applied Sciences ◽  
Simple Body ◽  
The University

In this paper the wind tunnel at the University of Applied Sciences Stralsund and few construction details as well as the calibration of the nozzle are presented. Furthermore some approaches to visualization and measurement of velocity fields of a simple body of vehicle are shown. The wake structure behind of simple car models was investigated experimentally using Particle Image Velocimetry (PIV). Furthermore the visualization of flow field by the fog probe systems supports the evaluation of the flow and drag behavior.

scholarly journals Control of Gliding Angle in RÜppell'S Griffon Vulture Gyps RÜppellii

1971 ◽  
Vol 55 (1) ◽  
pp. 39-46 ◽  
Author(s):  
C. J. PENNYCUICK
Keyword(s):  
Wind Tunnel ◽  
Drag Coefficient ◽  
The Body ◽  
Sectional Area ◽  
Wing Area ◽  
Cross Sectional ◽  
Griffon Vulture ◽  
Speed Increase ◽  
Induced Drag ◽  
Low Speeds

1. The drag of the frozen, wingless body of a Rüppell's griffon vulture was measured in a wind tunnel with a simple drag balance. The drag coefficient with feet and neck retracted was 0.43, based on the greatest cross-sectional area of the body. 2. The drag of the body was trebled by fully lowering the feet, and more than quadrupled when the tail was lowered as well, apparently owing to separation of the flow over the back. The drag coefficient of the legs and feet, based on their frontal area, varied from 0.89 to 1.08 in different positions. 3. At low speeds the use of the feet alone should reduce the glide ratio from about 15 to 10, but the airbrake effect becomes progressively more marked at higher speeds. At lower speeds reduction of the wing area produces a greater steepening of the gliding angle, but at the expense of increasing the minimum speed. Increase of induced drag would provide a highly effective gliding angle control at very low speeds, and it is suggested that this is achieved by raising the secondary feathers, which would alter the spanwise lift distribution by transferring a greater proportion of the lift to the primaries.

scholarly journals Experimental investigation of free jet pulsations in the wind tunnel with an open test section

2018 ◽  
Author(s):  
S. A. Baranov ◽  
N. I. Batura ◽  
G. G. Gadzhimagomedov ◽  
D. S. Sboev
Keyword(s):  
Experimental Investigation ◽  
Wind Tunnel ◽  
Test Section ◽  
Free Jet ◽  
Open Test

scholarly journals An Experimental Study of Test Section Velocity Calibration for Low-Speed Wind Tunnel

2012 ◽  
Vol 40 (3) ◽  
pp. 230-236 ◽  
Author(s):  
Se-Yoon Oh ◽  
Jong-Geon Lee ◽  
Sung-Cheol Kim ◽  
Sang-Ho Kim ◽  
Seung-Ki Ahn
Keyword(s):  
Experimental Study ◽  
Wind Tunnel ◽  
Test Section ◽  
Low Speed ◽  
Velocity Calibration ◽  
Low Speed Wind Tunnel

scholarly journals A New Method for Adjusting Setting Angle of Rotor Blade for Axial Fan in Wind Tunnel

2019 ◽  
Vol 37 (3) ◽  
pp. 580-586
Author(s):  
Xiaoli Qu ◽  
Zebin Ren ◽  
Wenguo Yang ◽  
Yuanqiang Luo ◽  
Chenghua Cong
Keyword(s):  
Wind Tunnel ◽  
Flow Velocity ◽  
Test Section ◽  
Rotor Blade ◽  
New Method ◽  
Axial Fan ◽  
Low Speed ◽  
Rotating Speed ◽  
Setting Angle ◽  
Low Speed Wind Tunnel

Combining the fan aerodynamic efficiency with the wind tunnel pressure loss coefficient, a new equation which points out the inherent relationship of the fan blade setting angle, fan rotating speed and gas flow rate in wind tunnel circuit is derived according to the two-dimensional flow theory of the axial fan rotor blades and the aerodynamic characteristics of the low speed wind tunnel. So a new method for setting angle adjustment of fan rotor blade to satisfy the fan performance at off-design point by getting the test results of fan operation parameters but without the fan total pressure rise in the low speed wind tunnel is developed. Flowing the new method, the setting angle adjusting value of fan rotor blade was provided only with the fan rotating speed and flow velocity in the test section of a low speed wind tunnel directly before the fan setting angle altered, the adjusting target was achieved by the new blade setting angle successfully and the time and cost of the wind tunnel commissioning test were saved. The test results show that, after increasing the fan rotor blade setting angle by 4.5 degrees, when the flow velocity in the wind tunnel test section reaches 60 m/s, the fan rotating speed is 570 r/min, the deviation from the predicted fan rotating speed value of 575 r/min is 0.9%. For the same test section flow velocity, the predicted value of the fan rotating speed is in a good agreement with the real value, it proves that this method is reliable and accurate in practical application.

MIXING LAYER STRUCTURE OF A JET IN A WIND TUNNEL WITH AN OPEN TEST SECTION

2017 ◽  
Vol 48 (8) ◽  
pp. 711-722
Author(s):  
N. I. Batura ◽  
Valery Viktorovich Vozhdaev ◽  
Gadzhi Gadzhimagomaevich Gadzhimagomedov ◽  
Igor Ivanovich Lipatov
Keyword(s):  
Wind Tunnel ◽  
Test Section ◽  
Layer Structure ◽  
Mixing Layer ◽  
Open Test

Development and Design of a Two-Stage Contraction Zone and Test Section of an Organic Rankine Cycle Wind Tunnel

2016 ◽  
Author(s):  
Maximilian Passmann ◽  
Felix Reinker ◽  
Karsten Hasselmann ◽  
Stefan aus der Wiesche ◽  
Franz Joos
Keyword(s):  
Boundary Layer ◽  
Wind Tunnel ◽  
Flow Separation ◽  
Test Section ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Boundary Layer Separation ◽  
Two Stage ◽  
Cross Sectional ◽  
Flow Deviation

This contribution presents the development and design of a two-stage contraction zone and modular test section for a closed loop Organic Rankine Cycle (ORC) wind tunnel. The first contraction consists of four truncated cones, whose length and angle of inclination are derived from a two-stage optimization procedure, with the objective to minimize flow deviation and to avoid boundary-layer separation. The geometrical optimization yields a profile with minor deviation to the ideal polynomial shape, whereas the flow optimized shape minimizes flow separation at the break-points between the single conical pieces. The second contraction has to perform two major tasks, namely the acceleration of the flow up to a Mach number of Ma = 0.8 for organic fluids and the transformation of the circular inlet to a rectangular outlet cross-sectional shape, required by the working section. The circular-to-rectangular transition is accomplished by variation of the generalized ellipse, also known as Lamé curve. Smooth polynomials are then used to define the reduction of cross-sectional area. A comprehensive number of contraction geometries with fixed contraction ratio, variable length, and different points of inflection are analyzed with regards to minimum flow deviation, the avoidance of flow separation, as well as a uniform velocity field at the contraction outlet. A semi-analytical approach based on a potential flow solution in combination with the Stratford criterion is the basis for evaluating boundary-layer separation. The design of a two-part modular diffuser, based on the concept of a dumped diffuser, as commonly encountered in gas turbine design, is presented. The numerical results are compared with analytical findings and special characteristics of the different designs are explained. Finally, the overall design concept of the test section is presented.

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