Wind Energy Report Series

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https://hdl.handle.net/10057/5660

In the 1970’s and 1980’s WSU faculty and staff were awarded a series of research grants from NASA-Lewis Research Center in Cleveland, Ohio (later renamed NASA-Glenn Research Center), with Drs. William Wentz and Melvin Snyder, professors of Aerospace Engineering as principal investigators. The WSU research involved thousands of hours of wind tunnel testing, computer studies of horizontal axis wind turbines, and full-scale field tests at the NASA Plumbrook Test Site. The results were published in a WSU report series as Wind Energy Reports (WER’s). Initially, publication of results was restricted by NASA through a process known as “For Early Domestic Dissemination,” which prohibited distribution for two years. All reports now have unlimited distribution. The WER’s were published through the WSU Wind Energy Laboratory, which was directed by Dr. Gary Thomann, professor of Electrical Engineering .

Unfortunately, some of the reports in the WER series have been lost, so the collection is incomplete. Archival copies are retained by the Special Collections unit of Ablah Library.

William H. Wentz, Jr. PhD, Distinguished Professor Emeritus, Aerospace Engineering

13 May 2013

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Now showing 1 - 5 of 22

WER-27: Effects of spoiler hingeline location on the NACA 23024 airfoil
(Wichita State University. Wind Energy Laboratory, 1984-08) Wentz, W.H.; Snyder, Melvin H.; Cao, Hoa V.
Two-dimensional wind tunnel tests were conducted to determine the aerodynamic effects of spoiler hingeline location on the NACA 23024 airfoil . The particular motivation for these studies is potential application of spoilers for overspeed control of wind turbines . For the tests, 10% chord spoiler at 90 degrees angle of deflection and 20% chord spoiler at 60 , 90, and 120 degrees angles of deflection were used. The locations of attachment for these spoilers were at 10, 20, 30 , 40, 60 and 80 percent along the wing chord. The wind tunnel tests were conducted at Reynolds numbers of 0.6xlo 6 and of 1.0x10 6 , which correspond to Mach numbers of 0.1 and 0 . 2, respectively . Results of the study show that when the spoiler hingeline is relocated toward the leading edge of the airfoil, the spoiler effectiveness in producing reduced lift and added drag is increased , especially at high angles of attack below the stall . The leading edge suction force is decreased as the spoiler hingeline is relocated toward the leading edge of the airfoil. The trend of the results agrees with theoretical predictions. It is recommended that tests of spoilers be conducted on a rotating blade.
WER-25: Aeroelastic analysis of the NASA MOD-0 100 kw wind turbine with aileron controlled blade tip
(Wichita State University. Center for Energy Studies, 1984-02) Abla, M.; Brock, B. J.; Liebst, B. S.; Wentz, W. H.
An aeroelastic analysis was conducted to determine the design requirements for the aileron control on the NASA MOD 0 100 KW wind turbine to prevent flutter or divergence. The configuration of the ailerons was 2~1 chord over the outboard 30% span of the blades. The results of the analysis shows that either rotational stiffness about the aileron hinge line must be maintained or mass balancing is required to prevent flutter. A 10 HZ hinge stiffness (5,621 IN-LB/RAD per side) or 60 IN-LB of mass balance added ahead of the hingeline at the tip is sufficient to prevent flutter under all operating conditions. In addition, a vibration analysis of the blade was performed to determine if any of the resonant frequencies coincide with any of the frequencies of the potential forcing functions. The only mode that appears potentially troublesome is the first "symmetric" (cantilevered) bending mode. It comes close to the 2P (twice per revolution) excitation frequency at 40 RPM. If this frequency is reduced because of joint flexibility where the blade joins the hub, there may be a frequency coincidence with the strong 2P excitation caused by the blade passing through the wake behind the tower.
WER-24rev.: Horizontal axis wind turbine wake and blade surface flow measurements from model tests
(Wichita State University. Center for Energy Studies, 1985-06) Wentz, W.H.; Octowari, C.; Manor, D.; Snyder, Melvin H.
Wind tunnel tests have been conducted to measure the wake and surface flow associated with a 50.8 cm diameter twisted, tapered rotor and a 50.8 cm diameter untapered, untwisted rotor. A disk model of 50.8 cm diameter was also tested. Torque and thrust were measured with a unique generator-mounted balance. Wake surveys were conducted using a scanning total pressure probe and special hot film anemometer. Blade surface patterns were observed using small tufts and a strobe light. The untwisted rotor produced thrust coefficients higher than 1, and wake regions of velocity reversal at high tip speed ratios. For high tip speed ratios the wake flow is quite similar to the solid disk. Blade surface flow patterns reveal the blade stall progression associated with angle of attack changes as the tip speed ratio varies.
WER-14: The use of wind power for oil production in Kansas
(Wichita State University. Wind Energy Laboratory. Center for Energy Studies, 1982-02) Fulton, Jay A.; Thomann, Gary C.
Five topics concerning the use of wind power by the Kansas crude oil production industry are explored: ( l ) the Kansas wind resource; (2) methods of oil production; (3) energy requirements of the oil industry; (4) wind power options; and (5) economics of those options . Wind power is found to be an economical energy alternative which could have a significant impact on 0; 1 industry energy requirements. Most of Kansas enjoys winds which average above 12 mi/hr, a value of wind speed for which wind machines are attractive. Furthermore. there is good correlation between areas of high wind and oil production. Two methods of wind power utilization are investigated: direct mechanical pumping and parallel electrical generation. Water pumping windmills should be able to produce up to 65 barrels of fluid per day from wells 1000 feet deep. Very preliminary results indicate the mechanical WECS could easily be economical with a 10 year life if propane is displaced. Parallel electrical generation may be used at nearly any electrified lease. it is the easiest method to implement and has no effect on oil production. In many cases parallel generating wind machines should be economical with a 10 year life.
WER-13A: Appendix to Wind Energy Report 13. Wind Energy Report No. 13 Characteristics of Wakes Downstream of Circular Cylinders and 12-Sided Cylinders
(Wichita State University. Wind Energy Laboratory, 1981-01) Snyder, Melvin H.; Wentz, W.H.
To obtain models of the near-field wakes behind cylinders of the types used as support structures for wind turbines, wind tunnel tests were conducted in the Walter Beech Memorial Wind Tunnel of Wichita State University. The tests were surveys of wakes downstream of circular cylinders and of l2-sided cylinders. This Appendix contains the Wind Tunnel Run Log and the data obtained from the computer during the wind tunnel tests. There are two forms of print-out depending on the instrumentation being used--five-tube pressure probe and hot-wire anemometer.

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