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1

Preliminary specification of the dry ice blasting converging-divergent nozzle parameters basing on the standard (analytical) methods

Mikołajczak A., Krawczyk P., Stępień M., Badyda K.

Rynek Energii

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2018

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Nr 4

91--96

EN

Pollution can be a serious problem in industry, that is why various cleaning methods were developed. The dry-ice blasting is one of them, which can be easily implemented in a different applications, i.e. electric industry. In this method dry, compressed air with the solid CO2 particles hits the cleaned surface. The pollution is removed by supercooling and crushing due to the particles strikes and local volume growth, caused by the dry ice sublimation. To provide the proper air-particles mixture parameters, converging-divergent nozzles are used. The geometry of the nozzle can have the crucial influence on the mixture parameters and the cleaning efficiency. Among the most important nozzles parameters the opening angle, critical cross section and the shape of the outlet were determined. These specification can be used during the further work as the guidelines to the CFD modeling.

PL

Zanieczyszczenia przemysłowe mogą stanowić poważny problem eksploatacyjny, dlatego opracowano i powszechnie stosuje się różne metody czyszczenia. Jedną z nich jest czyszczenie mieszaniną suchego lodu i powietrza. Metoda ta może być łatwo wdrożona w różnych zastosowaniach, np. przemyśle elektro-energetycznym. W opisywanym rozwiązaniu suche, sprężone powietrze z cząsteczkami stałego CO2 trafia na czyszczoną powierzchnię. Zanieczyszczenie usuwane jest przez przechłodzenie i pękanie warstwy brudu w wyniku uderzenia cząstek o dużej prędkości i lokalnego wzrostu objętości, spowodowanego sublimacją suchego lodu. Aby zapewnić prawidłowe parametry mieszaniny suchy lód-powietrze, stosuje się dysze zbieżno-rozbieżne. Geometria dyszy może mieć decydujący wpływ na parametry mieszanki i skuteczność czyszczenia. Wśród najważniejszych parametrów dysz wymienić można kąt rozwarcia, przekrój krytyczny oraz kształt przekroju wylotowego. Opracowane wytyczne mogą zostać wykorzystane podczas dalszej pracy do stworzenia modelu CFD, umożliwiającego ostateczną weryfikację kształtu kanału przepływowego dyszy.

2

Experimental research on development of the controllable disturbances in the wake at supersonic flow around the plate

Lysenko V. I., Kosinov A. D., Yermolaev Yu. G.

Archives of Mechanics

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2003

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Vol. 55, nr 3

243-256

EN

The development of the artificial disturbances in the boundary layer on the flat part of a plate, the boundary layer on the opposite wedge (model stern) behind a fan of expansion waves and the wake was investigated at Mach number 2.

3

Supersonic low interaction with absorbing surface

Svirschevsky S., Nikitchenko Y.

Research Bulletin / Warsaw University of Technology, Institute of Aeronautics and Applied Mechanics

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2001

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nr 12

93-96

EN

This paper is devoted to investigation of shock wave rise conditions ahead of an absorbing surface. The study was based on the numerical solution of the model of kinetic equations BGK in an integral form. It was found that the boundary between the regions of steady, non-steady modes in one-dimensional problem corresponds to the boundary of the shock wave existence area for a multi-dimensional problem.

4

Study a multi-body aerodynamic interference in supersonic flow

Svirschevsky S., Semenchikov N., Korolev N., Tarkhow E.

Research Bulletin / Warsaw University of Technology, Institute of Aeronautics and Applied Mechanics

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2001

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nr 12

97-104

EN

The experimental results of investigations into aerodynamics of two bodies for their different orientations relative to each other in a supersonic flow are presented. The first body was the spherical segment fitted to blunt conical boattail. The second was the hollow convergent cone with a spherical afterbody. The tests were carried out in the sub-trans-supersonic closed layout wind tunnel T-2 MAI at the free stream Mach numbers M[infinity] = 1.3-2.5 and at angles of attack ranging from 0° to 180°. The investigations were conducted for several distances between bodies. The coefficients of a normal force, an axial force and a pitching moment of these bodies were found. The flow visualizations were made to obtain the flow structures around the experimental models. The new data on aerodynamics of dividing objects enabling one to define their longitudinal static stability are obtained with a high degree of accuracy. The results of these investigations have showed the big influence of aerodynamic interference on the performances of the discussed configurations.

5

Influence of a heterogeneous combustion system in near wake of bodies of revolution on its drag force in supersonic flow

Glagolev A., Zubkov A., Suhanovskaya L.

Research Bulletin / Warsaw University of Technology, Institute of Aeronautics and Applied Mechanics

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2001

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nr 11

81-86

EN

We had used non-conventional methods for heat and mass transfer determination to axisymmetric bodies in the base pressure and drag force control. The experiments were conducted in supersonic flow for Mach numbers within the range 1.15

6

Nonlinear, regular and chaotic vibrations of an airfoil with a trailing and edge flap in supersonic flow

Dżygadło Z., Nowotarski I., Olejnik A.

Journal of Technical Physics

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2000

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Vol. 41, no 3

219-229

EN

An airfoil in supersonic flow, having deformable nonlinear supports, is an aeroelastic system for which various types of instability, bifurcations and regular or chaotic motions can appear. The airfoil has three degrees of freedom - that is, plunge displacement, angle of pitch and angle of flap deflection. The stiffness force and moments for all those motions are assumed to be nonlinear ones. The airfoil is subjected to the pressure difference produced by its motion in supersonic flow. Stability and bifurcations occurring in the system, limit cycles of self-excited vibrations and regions of regular or chaotic motions have been investigated. The effect of some parameters of the system on the course of linear and nonlinear vibrations has been studied.

7

Aerodynamics of a half-wing in supersonic flow

Svirschevsky S., Semenchikov N., Tarkhow E., Chernov G.

Research Bulletin / Warsaw University of Technology, Institute of Aeronautics and Applied Mechanics

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1999

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nr 9

135-138

EN

Experimental results of the aerodynamic normal forces and moments of the semispan wing models are presented. All tests have been conducted at free stream Mach numbers M[infinity] = 1,5... 2,5, the angles of attack alpha= -4o ... 26° and the angles of sideslip beta= 0°...20°. Mounting effects on the model aerodynamic properties are considered. The test results of the semispan models can be used for a prediction of aerodynamic properties of sideslipping half-wings in a supersonic flow.

8

Non-linear, regular and chaotic vibrations of a plate in supersonic flow

Dżygadło Z., Nowatorski I., Olejnik A.

Research Bulletin / Warsaw University of Technology, Institute of Aeronautics and Applied Mechanics

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1998

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nr 8

153-160

EN

Aeroelasticity of surface structures in supersonic flow is a domain which involves various linear and nonlinear vibrations, static and dynamic instabilites and limit cycle motions (cf. [1] - [4]). There can appear various types of bifurcations and regular or chaotic motions depending on the value of parameters of the system under investigation [3] -[7] In this paper nonlinear bending vibrations of a plate of finite length and infinite width in supersonic flow are considered under assumption that a in-plane compressing force is acting in the The dynamic pressure difference produced by the motion in gas stream is determined on the of the potential theory of supersonic flow [1], [2]. Finally, we obtain a nonlinear partial integro-equation describing the motion of the under investigation. The solution of this is obtained in the form of a series of eigenfunctions of the self-adjoined boundary-value vibration problem of the same plate In the vacuum. Making use of the Galerkin method we then obtain a set of nonlinear ordinary differential which can be analysed by means of methods. Types of bifurcations occurring in the problem are investigated, limit cycles of self-vibrations and regions of regular and chaotic can be determined.