Method, algorithm and program complex for calculating heat state of cooled rocket micro engines

Аuthors

Formalev V. F.^*, Kolesnik S. A.^**

Moscow Aviation Institute (National Research University), 4, Volokolamskoe shosse, Moscow, А-80, GSP-3, 125993, Russia

*e-mail: formalev38@mail.ru
**e-mail: sergey@oviont.com

Abstract

The paper presents physical and mathematical model, algorithm and description of the program complex meant for calculating thermal state of a cooled micro rocket engines block, used to operate space objects. The micro engines block looks like a plain profile box of the engines (every one has length no more 15mm) with two cross cooling channels that are situated next to combustion chambers and nozzles, where liquid or gaseous refrigerant can be used.

The thermal energy source is introduced by high-temperature gas-dynamic flow with stagnation temperature of about 2000 degrees Kelvin. Under these conditions, metal structure of micro engines block has a temperature limitation. As a result, heat energy discharge using a refrigerant is necessary. With this, the larger the velocity of a refrigerant the larger is the discharge.

In order to define thermal state of the micro engines block it is necessary to solve heat transfer problems between hydro-dynamic and gas-dynamic flows as well as between multiply connected bodies bounded with uneven boundaries: — non-viscous flow in the combustion chamber and nozzle of the micro engine;
— flow and heat transfer in a gas-dynamic boundary layer;
— flow and heat transfer in cooled canals;
— conjugate heat transfer between hydro-gas-dynamic flows and a hull of the block of the micro engines;
— three dimensional nonsteady heat transfer in multiply connected area bounded with uneven boundary;
— to make up algorithm and program complex for calculating heat state of the block of micro engines.

The paper presents a new method for numeric solving of combined heat transfer problems and problems of three dimensional non-steady heat transfer. We used a method of reflection of multiply connected area with any boundary into classical form area (rectangle, parallelepiped...), where it is possible to make up a through orthogonal grid. At that, coordinate lines can enter and leave the calculated area any arbitrary number of times.

The program complex for calculating thermal state of the block of cooled micro rocket engines was designed using the presented above algorithm. Namely, to determine heat-exchange parameters of gas-dynamic flows in gas-dynamic and cooled channels, as well 3D non-stationary thermal conductivity in multiply connected regions with arbitrary boundaries. We obtained and analyzed multiple numerical solution results.

Keywords:

micro rocket engines, cooling canals, heat, heat gas-dynamic flow, conjugate heat transfer, conjugate heat transfer, break down of the numerical method, immersion method, gas-dynamic parameters, 3D non-stationary temperature field, special software

References

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