M.O. Oyewola1, M.S. Adaramola2, A.F. Olaberinjo3, J.A. Akinyemi4, and J.O. Oyewola4 1School of Chemical Engineering and Industrial Chemistry University of New South Wales, Australia 2Division of Environmental Engineering University of Saskatchewan, Saskatoon, Canada 3Chemical, Petroleum and Gas Department University of Lagos, Nigeria 4Department of Mathematics and Statistics Lagos State Polytechnics, Nigeria
Pages: 125–132
Hot-wire measurements have been undertaken in a turbulent boundary layer which is subjected to an impulse in form of a short roughness strip with the aim of examining its influence on the structure of the turbulent boundary layer. The results indicate that, while the energy containing motion is shifted from low wave number to high wave number near the wall due to the interfering of the roughness strip with the near-wall structure, the reverse is the case in the outer region. While the anisotropy at small scale changes appreciably, there is no discernable change at the large scale when distance from the wall is increased as reflected in the collapses of spectra shear correlation coefficient at the low wave number. It further shows that the roughness strip alters the flow dynamics of the boundary layer as shown in the changes in the mixing length distribution.
Measurement results on turbulent friction are presented for nine single-layer compliant coatings in comparison with a polished solid surface streamlined by the water flow. Three experimental series separated by time passed after coating fabrication were carried out. Results on monitoring of the viscoelastic properties of coating materials are shown; they allow analysing coating aging effect as the instability factor of coating hydrodynamic efficiency.
P.A. Neobyavlyayushchy1, A.A. Dekterev2, A.A. Gavrilov2, and Yu.I. Storozhev3 1Institute of Computer Modelling SB RAS, Krasnoyarsk, Russia 2Institute of Thermophysics SB RAS, Krasnoyarsk, Russia 3Krasnoyarsk State Technical University, Russia
Pages: 143–151
A complex numerical and experimental investigation of burner devices for a reburning of the anode gas of aluminum production was carried out. The chosen mathematical model of the processes of aerodynamics, heat exchange, and gas burning was identified and adapted on the basis of data of real-scale measurements. Basing on computational experiments the optimization of the design of elements of the system for anode gas detoxication and transport was carried out. A new system was proposed and tested for reburning the anode gases of electrolysis production, which consists of an improved burner device and a dust-sedimenting chamber with a possibility of regulating the amount of gas suction.
The density of solid and liquid indium antimonide was studied by irradiating the samples with a narrow beam of monochromatic gamma-radiation in the temperature range of 293- 1950 K, including the range of melting
S.A. Isaev1, P.A. Baranov2, A.G. Sudakov1, and V.B. Kharchenko1 1Saint-Petersburg State University of Civil Aviation, St. Petersburg, Russia
Pages: 169–186
On the basis of the solution by multi-block computational technologies of Reynolds equations closed with the aid of the equations of the model of Menter
Results of T-203 wind-tunnel tests of an elastic airplane model dynamically similar to Tu-204 aircraft equipped with a passive wing load reduction system are reported. The wing load reduction system comprised two auxiliary aerodynamic surfaces of the slotted-interceptor type installed symmetrically on the upper surface of the lifting wing at the boundary-layer height. It was found that, with the operating system, the additional bending moments induced by symmetric vertical discrete gusts in the wing root and at the fuselage mid-body decreased by 20 %, with simultaneous increase observed in the flexure-pylon flutter speed.
a:2:{s:4:"TEXT";s:83:"A.V. Sobolev1, V.I. Zapryagaev1, and V.M. Mal’kov2";s:4:"TYPE";s:4:"html";} 1Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, Novosibirsk, Russia
Pages: 193–200
Properties of gas-jet ejectors with converging mixing chamber operated under critical and subcritical flow conditions are examined. Establishment of the critical operation mode in such ejectors started up with and without the secondary gas flow is considered. The mechanism underlying the emergence of flow pulsations at low rates of the low-head flow is described. Results of an experimental study aimed at the improvement of ejector discharge characteristics by chamber-length reduction and related mixing enhancement are reported. As flow-mixing elements, slotted heads, chevrons, and tubs are considered. The best discharge characteristics were obtained with nozzles provided with tubs.
Theoretical and simulation study was carried out for eliciting conditions when an intentionally formed system of oblique shocks can be used for control of parameters of condensed phase in supersonic flow. The key features of flow were analysed for two versions of duct, which are different in geometry of nozzle and acceleration headpiece. The results confirmed the feasibility of intentional impact on the structure of developing set of shock waves through changes in the duct profile: this would change the particle trajectories.
A new method for measurement of viscoelastic properties of materials, based on the exact solution of the problem of the forced oscillations of a flat sample loaded by inertial mass, is proposed. The device for these measurements is described. The elasticity modulus and loss tangent are measured within the frequency range from 100 Hz to 10 kHz at relative deformation of a sample below 1 %. The approximate formulas for calculation of viscoelastic properties are derived, and the conditions of their applicability are determined. The methods for expansion of the frequency range and measurement of materials with extremely high loss tangent are proposed. The proposed method is compared with the current Standard. It is shown that the new method has the higher accuracy and expanded range of parameter measurements, and the construction of device is easy and reliable, since it does not require the knowledge on the oscillation properties of vibration source.
