A unique method of wind tunnel measurements is being implemented at TsAGI
9 December 2013
Experts of the aircraft and rocket aerodynamics department of the Central Aerohydrodynamic Institute named after N.E. Zhukovsky completed the first cycle of studies of unsteady flow characteristics with the use of a thermal anemometer (a device allowing to determine flow characteristics by measuring heat loss parameters with sensors) at subsonic and transonic flow speed. The work has been carried out jointly with the SB RAS Institute of Theoretical and Applied Mechanics named after S.A. Christianovich (Novosibirsk) in two aerodynamic wind tunnel of TsAGI — ADT T-128 and T-112.
The tests have completed the first stage of implementation of the unique hot-wire technique of the study of oscillatory characteristics of high-speed flows at TsAGI.
This method and hardware developed by experts of ITAM SB RAS headed by prof. V.A. Lebiga have been previously applied successfully in domestic and foreign wind tunnels of ITAM SB RAS (Novosibirsk), ETW (Cologne), etc. The technique is based on plotting Kovazhny charts for flow oscillations at high subsonic and transonic speeds and allows not only to determine the levels and spectra of disturbances, but also to divide oscillation modes into three parts — vortex, entropy and acoustic components. This integrated approach makes it possible to find the source of disturbances, to determine their nature and location, and to take the necessary measures to reduce their impact.
The use of hot-wire measurement technique in the wind tunnels T-128, T-112 and other TsAGI tunnels will provide unique information on unsteady flow characteristics. This is particularly important when testing models of laminarized aircraft and models with free laminar-turbulent transition. Eliminating or reducing the intensity of disturbance sources will increase the accuracy and reliability of the obtained weight characteristics of aircraft models and provide better information for verification of computational methods.
The collaboration between TsAGI and ITAM SB RAS in this area will be continued next year. In the future it is planned to transfer the methods, technology and special equipment for such tests to the specialists of FSUE TsAGI. In the long term the study of oscillatory flow characteristics will be included in the full-time program of certification of the industrial wind tunnels of TsAGI.