Application of Doppler Global Velocimetry to Supersonic Flows
نویسنده
چکیده
The design and implementation of Doppler Global Velocimetry (DGV) for testing in the Langley Unitary Plan Wind Tunnel is presented. The discussion begins by outlining the characteristics of the tunnel and the t e s t e n v i r o nmen t , w i t h p o t e n t i a l p r o b l em a r e a s h i g h l i g h t e d . Modifications to the optical system design to implement solutions for these problems are described. Since this tunnel entry was the first ever use of DGV in a supersonic wind tunnel, the test series was divided into th r e e pha s e s , e a ch w i th i t s own goa l . Pha s e I d e t e rm ined i f condensation provided sufficient scattered light for DGV applications. Phase II studied particle lag by measuring the flow about an oblique shock above an inclined flat plate. Phase III investigated the supersonic vortical flow field above a 75-degree delta wing at 24-degrees angle of attack. Example results from these tests are presented.
منابع مشابه
HIGH RESOLUTION LASER SPECTROSCOPY IN COLD SUPERSONIC MOLECULAR BEAMS COOLING, REDUCTION OF DOPPLER WIDTH AND APPLICATION
The cooling of molecules during the adiabatic expansion of supersonic seeded molecular beams is reviewed and illustrated by the example of NO -molecules. The reduction of the Doppler width by collimation of the beam and the cooling to low rotational temperatures brings a significant simplification of the complex NO -absorption spectrum and allows its assignment. The measured rotational tem...
متن کاملDevelopment of Doppler Global Velocimetry as a Flow Diagnostics Tool
The development of Doppler global velocimetry is described from its inception to its use as a flow diagnostics tool. Its evolution is traced from an elementary one-component laboratory prototype, to a full three-component configuration operating in a wind tunnel at focal distances exceeding 15 m. As part of the developmental process, several wind tunnel flow field investigations were conducted....
متن کاملAre Uterine and Ovarian Artery Doppler Velocimetry Values Good Pregnancy Predictors in Clomiphene Citrate Cycles?
Background We conducted this prospective study to evaluate the prognostic significance of uterine and ovarian artery Doppler velocimetry in clomiphene citrate (CC) cycles. MaterialsAndMethods A total of 80 patients with unexplained infertility were given 100 mg/day of CC from day 3 to day 7 of their cycles in this current prospective study. On cycle day 3, before administration of CC, each pati...
متن کاملApplication of Particle Image Velocimetry to High-Speed Supersonic Flows in a Shock Tunnel
Particle Image Velocimetry (PIV) has become an important tool in modern flowfield diagnostics, in particular for subsonic flows. PIV systems have also been used to measure supersonic flows in supersonic wind tunnels, but only recently it has been shown that PIV can also be a valuable tool for high-speed supersonic flows in a shock tunnel (Haertig et al., 2001). At the ISL shock tunnel a PIV sys...
متن کاملThe Relationship of Uterine Artery Doppler Velocimetry Findings and Hemoglobin Concentration with Pregnancy Outcomes in Pre-eclampsia
Abstract Background: Epidemiologic studies have shown the relationship of maternal hemoglobin level and abnormal findings in uterine Doppler sonography with pregnancy- related complications. In this study, we evaluated the relationship of uterine artery Doppler velocimetry findings and hemoglobin level with the outcomes of pregnancy in women with preeclampsi...
متن کامل