Skip to Main Content
 

Global Search Box

 
 
 

ETD Abstract Container

Abstract Header

Characterization of Upstream Effects Due to High Blockage in the AFRL Vertical Wind Tunnel

Abstract Details

2019, Master of Science (M.S.), University of Dayton, Aerospace Engineering.
An investigation into upstream propagation of blockage effects from a bluff body at varying tunnel dynamic pressures was undertaken but ultimately linked instead to wind tunnel fan RPM for a nimiety of reasons which will be described herein. The bluff body is intended to simulate propellers tested in the Air Force Research Laboratory’s (AFRL) Vertical Wind Tunnel (VWT) where blockage effects were suspected due to disagreements between experimental results and numerical predictions from various sources. It is discovered that the previous understanding of the character of the VWT’s flowfield properties is lacking. Significant heat transfer occurs and test section total pressure varies significantly with changes in fan RPM. Additionally, the traditional method for measuring tunnel total pressure is unreliable at blockage ratios greater than 2.8%. At present, due to these total pressure variations, there is no method available that uses tunnel instruments to anchor test data for comparison across multiple days. Resorting to an unconventional approach, it is found that blockage effects can propagate more than 8 feet upstream of the test section lip (0.75 test section diameters); far upstream of the tunnel pitot-static probe used to measure test section conditions. It is thus concluded that incorrect tunnel dynamic pressure readings are likely and must be taken into consideration in evaluating the propeller performance accurately.
Aaron Altman, Ph.D (Committee Chair)
Sidaard Gunasekaran, Ph.D (Committee Member)
Gregory Parker, Ph.D (Committee Member)
96 p.

Recommended Citations

Citations

  • Sholtis, P. M. (2019). Characterization of Upstream Effects Due to High Blockage in the AFRL Vertical Wind Tunnel [Master's thesis, University of Dayton]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=dayton155594746187138

    APA Style (7th edition)

  • Sholtis, Paul. Characterization of Upstream Effects Due to High Blockage in the AFRL Vertical Wind Tunnel. 2019. University of Dayton, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=dayton155594746187138.

    MLA Style (8th edition)

  • Sholtis, Paul. "Characterization of Upstream Effects Due to High Blockage in the AFRL Vertical Wind Tunnel." Master's thesis, University of Dayton, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=dayton155594746187138

    Chicago Manual of Style (17th edition)