Home – Home – Jornals – Thermophysics and Aeromechanics 2003 number 4

A historical review of aviation development from the first attempts to create flying vehicle heavier than air to the present time is given. The main stages of evolution of military and civil aviation for the past 100 years are described with the use of the most famous aircraft as examples. Possible trends of evolution of the main aircraft types for the nearest future are briefly considered.

A simple method for studying spin regimes in a horizontal wind tunnel is considered. The method is based on the assumption about the weak influence of the spin radius on aerodynamic characteristics. The experimental technique is analyzed, and the equipment developed and the models examined are described. The results are compared with the data obtained by traditional methods of spin studies. The effect of inertial properties of the configuration and the position of the center of mass on steady spin parameters is demonstrated. Comparative estimates of efficiency of various methods for recovery are obtained, and recommendations for improving the spin characteristics of the examined configurations are developed.

The experimental data are compared with the numerical computations for the cases of a three-dimensional interaction of crossing shocks of various strengths and the subsequent expansion waves with a turbulent boundary layer in conditions of a flow around two vertical fins with different deflection angles of side surfaces ₁

The experimental results on control by disturbances development in a swept wing boundary layer by means of localized and distributed suction are presented. The control by spanwise flow stationary vortices and secondary periodical disturbances generated at late stages of these vortices development was studied. It is shown that the distributed suction is a simple way to suppress the secondary vortex instability of a spanwise flow as compared with a localized suction. It was shown that the localized suction through a small diameter hole may cause generation of additional stationary vortices in the boundary layer. In this case complex nonlinear interactions between both controlled and controlling disturbances take place. The distributed suction effect through a group of holes is similar to the slot suction and it introduces much less disturbances of vorticity into the boundary layer.

The linear temporal stability of a nonorthogonal flow impinging on a flat wall at arbitrary angle of incidence is investigated. It is shown that the flow is stable to disturbances in the form of stationary streamwise vortices.

Operation efficiency of the gas-dynamic protectors used for decreasing outer contamination of the International Space Station by jets of orientation thrusters was studied under the real conditions. Results are shown. Data on composition of incomplete combustible products and their effect on optic characteristics of thermostatic coatings are presented.

Measurements of velocity and temperature profiles in a Ranque ( Hilsch vortex tube with square section are presented. It was demonstrated that energy separation in gas flow for this kind of devices takes place similar to the well-known round tubes. For similar integral parameters of gas flow, the values of temperature drop between two outlets are close for the two variants of tube. The simple kinematical model of energy separation was developed for stationary swirl axisymmetrical flow of ideal gas in the vortex tube. Comparison with experimental data proved that the developed model gives a pretty accurate description of velocity field in the vortex tube and provides a good estimate for stagnation temperature drop along the radius.

The results of mathematical modelling of nonstationary heat and water transfer in a multilayer external walling are presented for different initial and boundary conditions. The process of moisture condensation in walling is analyzed, and a technique is proposed for its elimination. The possibility of estimating the thermal stability of walling to the cyclic changes of ambient medium parameters is shown.

Results of numerical simulation of film boiling site evolution on the heat-releasing surface are presented. Boundary conditions were analyzed within the front of boiling regime change. While describing the dynamics of the front of boiling regime change by the simulation model, the non-stationary character of heat transfer within different zones at the front of regime change was taken into account. The influence of frequency, amplitude, and linear size of the zone of pulsation intensity of heat transfer in the areas of nucleate and transitional boiling on the average propagation velocity of film boiling is shown quantitatively for the first time. Data on thermal stability and dynamics of succession development for the local film boiling sites were obtained within the framework of simulation model. It is shown that the critical size of

Thermal conductivity of liquid 1,1,1,2,3,3-hexafluoropropane (R-236ea) has been measured by the method of high-frequency thermal waves in the temperature range from 264 to 354 K and pressures of up to 31.7 bar. The estimated measurement errors do not exceed 1.5 %. It was shown that molecular thermal conductivity of R-236ea linearly increases with the pressure rise, while the temperature rise has an opposite effect. New predictive method for liquid thermal conductivity of fluorinated derivatives of propane is suggested.

It considers the specifics of vortex-steam plasmatorches and describes in detail the generalized characteristics of an arc burning in a water-steam stream.