0
TECHNICAL PAPERS

Design of a Low-Turbulence, Low-Pressure Wind-Tunnel for Micro-Aerodynamics

[+] Author and Article Information
Michael J. Martin

Department of Aerospace Engineering, University of Michigan, Ann Arbor, MI 48109-2140martinm2@asme.org

Kevin J. Scavazze, Iain D. Boyd, Luis P. Bernal

Department of Aerospace Engineering, University of Michigan, Ann Arbor, MI 48109-2140

J. Fluids Eng 128(5), 1045-1052 (Feb 13, 2006) (8 pages) doi:10.1115/1.2236128 History: Received March 23, 2005; Revised February 13, 2006

A novel wind-tunnel facility has been designed for measurement of lift and drag on micromachined airfoils. The tunnel is designed to operate with pressures ranging from 0.15 to 1.0 atmosphere, over a velocity range of 30 to 100ms, allowing for independent control of Reynolds and Knudsen number. The tunnel is designed for testing of airfoils with chords of 10 to 100 microns, giving a range of Reynolds numbers from 10 to 600, with Knudsen numbers reaching 0.01. Due to the structural constraints of the airfoils being tested, the wind tunnel has a 1cm cross-section. This small size allows the use of a 100-1 contraction area, and extremely fine turbulence screens, creating a low turbulence facility. Computational fluid dynamics is used to show that an ultra-short 100-1 contraction provides uniform flow without separation, or corner vortices. Velocity data obtained with impact and hot-wire probes indicate uniform flow and turbulence intensities below 0.5%.

Copyright © 2006 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

Integrated flat plate airfoil and sensor design

Grahic Jump Location
Figure 2

Schematic of test facility

Grahic Jump Location
Figure 3

Contraction geometry

Grahic Jump Location
Figure 5

Velocity profiles for sample contractions

Grahic Jump Location
Figure 6

Contours of U, 0.045m contraction, U=100m∕s, P=1.0atm

Grahic Jump Location
Figure 7

Streamlines for 0.045m contraction, U=100m∕s, P=1.0atm

Grahic Jump Location
Figure 8

Normalized velocity profiles at end of 0.045m contraction

Grahic Jump Location
Figure 9

Normalized velocity profiles 1cm into test section

Grahic Jump Location
Figure 10

Normal velocity vectors at end of contraction section

Grahic Jump Location
Figure 11

Nondimensional velocity profiles

Grahic Jump Location
Figure 12

Boundary layer thickness versus Reynolds number

Grahic Jump Location
Figure 13

Momentum and velocity deficits versus Reynolds number

Grahic Jump Location
Figure 14

Reδ versus tunnel Reynolds number

Grahic Jump Location
Figure 15

Operational facility

Grahic Jump Location
Figure 16

Test section instrumentation

Grahic Jump Location
Figure 17

Test section instrumentation installation

Grahic Jump Location
Figure 18

Velocity profiles for P=0.3atm

Grahic Jump Location
Figure 19

Velocity profiles for P=0.5atm

Grahic Jump Location
Figure 20

Velocity profiles for P=0.9atm

Grahic Jump Location
Figure 21

Velocity profiles for P=1.0atm

Grahic Jump Location
Figure 22

Test section instrumentation with hot film probe

Grahic Jump Location
Figure 23

Centerline hot-wire voltage fluctuations

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In