Spacecraft External Heat Flow Analysis by z-Buffer Method

Authors: Soluyanov A.A. Published: 12.04.2017
Published in issue: #2(113)/2017  

DOI: 10.18698/0236-3941-2017-2-15-27

Category: Aviation and Rocket-Space Engineering | Chapter: Aerodynamics and Heat Transfer Processes in Aircrafts  
Keywords: spacecraft, meshed geometrical model, mutual shading, pixel, z-buffer, depth buffer

Determining the external heat flow from direct sunlight to spacecraft is an important stage in analysis and design of the spacecraft thermal control. The Earth IR and albedo radiation provide the noticeable contribution in total spacecraft heating in case when a spacecraft is operating in Low Earth Orbit. The task gets significantly more complicated in case of complex spacecraft geometrical configuration in presence of mutual shading by spacecraft components. The zonal method is often applied to simplify calculations when visible terrestrial region is subdivided into a finite number of surface area zones. The radiation from each zone is approximated as a parallel beam is irradiated from a point source placed in the zonal center. Direct sunlight is considered to be a parallel beam from the point source as well, therefore it is possible to calculate the total external heating using the same approach. The key point of the approach implementation is to choose an algorithm for calculating the spacecraft external surface projected area facing radiation from each point of the source if there is a possibility of spacecraft components mutual shading. Known algorithms based on ray-tracing could experience a significant loss of performance being applied to complex models, especially containing components of non-regular shape. This paper presents a method for carrying out such calculations on a meshed spacecraft CAD model with its external surface subdivided into a finite number of faces of any kind (triangles, quadrangles or isoparametric faces). The method uses the z-buffer (or depth buffer) technique well-known in the field of computer graphics. Advantages of the method are straightforward implementation, applicability to a geometrical model of any complexity and acceptable performance which is not affected by the nonregularity of geometry.


[1] Kozlov L.V., Nusinov M.D., Petrov G.I. Modelirovanie teplovykh rezhimov kosmicheskogo apparata i okruzhayushchey ego sredy [Spacecraft and its environment thermal conditions simulation]. Moscow, Mashinostroenie Publ., 1971. 382 p.

[2] Zaletaev S.V., Kopyatkevich R.M. Software package of a thermal design and an analysis of spacecraft thermal conditions. Kosmonavtika i raketostroenie, 2014, no. 4, pp. 84-91 (in Russ.).

[3] Bogoyavlenskiy A.I., Kamenev A.A., Poluyan M.M., Soluyanov A.A., Khankov S.I. Modeling for optical spectrum range energetic characteristics of space objects. Radiopromyshlennost’ [Radio industry], 2014, no. 1, pp. 147-154 (in Russ.).

[4] Baeva Yu.V., Lapovok E.V., Khankov S.I. Calculation method of the transient temperatures for moving space object on the elliptical orbit. Nauchno-tekhnicheskiy vestnik informatsionnykh tekhnologiy, mekhaniki i optiki [Scientific and Technical Journal of Information Technologies, Mechanics and Optics], 2013, no. 6, pp. 67-72 (in Russ.).

[5] Dzitoev A.M., Khankov S.I. Calculation methods for irradiance coefficients of cylindrical space object by the earth radiation. Nauchno-tekhnicheskiy vestnik informatsionnykh tekhnologiy, mekhaniki i optiki [Scientific and Technical Journal of Information Technologies, Mechanics and Optics], 2014, no. 1, pp. 145-150 (in Russ.).

[6] Shilko I.I. The organization of the light pressure on the satellite surface account. Vestnik SibGAU, 2011, no. 1, pp. 123-125 (in Russ.).

[7] Paleshkin A.B., Kolesnikov A.B. Numerical method of modelling of external heat exchange of the space vehicle with any form of external surfaces. Vestnik MAI, 2010, vol. 17, no. 4, pp. 81-89 (in Russ.).

[8] Nikulin E.A. Komp’yuternaya geometriya i algoritmy mashinnoy grafiki [Computer geometry and computer graphics algorithms]. Sankt-Petersburg, BKhV-Peterburg Publ., 2003. 560 p.

[9] Vasil’kov D.M. Geometricheskoe modelirovanie i komp’yuternaya grafika: vychislitel’nye i algoritmicheskie osnovy [Geometric modeling and computer graphics: calculating and algorithmic principles]. Minsk, BSU Publ., 2011. 203 p.

[10] Yaroshevich V.A. Komp’yuternaya grafika [Computer graphics]. Moscow, MIET Publ., 2014. 68 p.

[11] Kulyasov P.S., Nikulin E.A. Accelerating the form factor computation in scene illumination calculations by the radiosity method. Vestnik Nizhegorodskogo universiteta [Vestnik of Lobachevsky University of Nizhni Novgorod], 2012, no. 3, pp. 184-188 (in Russ.).

[12] Shaenko A.Yu. Calculation method of heat exchange in radiation screen of large space observatories. Kosmonavtika i raketostroenie, 2011, no. 1, pp. 57-64 (in Russ.).