Variations in the normal and tangential momentum accommodation coefficients from analysis of atmospheric lift and drag forces on ANS-1 (1974-70A)
Abstract
Studies of aerodynamic lift and drag in hyperthermal free molecular flow regimes usually adopt Schamberg's model for gas-surface interaction, utilising the thermal accommodation coefficient. Most authors assume near-diffuse reflection characteristics with constant re-emission speed for all angles of incidence. For modelling atmospheric forces a more natural approach is to utilise normal and tangential momentum coefficients, σ1 and σ respectively. Experimental laboratory data has yielded qualitatively the dependence on the angle of incidence which to good approximation can be represented as ω ≜ ω ' 0,ω 1≜ ∑ω01 - &lim&ω11 sec ɛi where σ0, σ10 and σ1l are constants and ξi is the angle subtended between the incident flow and the surface normal. Adopting these relationships the effects of atmospheric lift on the satellite inclination, i, and atmospheric drag on the semi-major axis, a, and eccentricity, e, have been investigated. Applications to ANS1 (1974-70A) show that the observed perturbation in i can be ascribed to non-zero σ1l whilst perturbations in a and e produce a constraint equation between the three parameters.
Present address: GEC-MARCONI RESEARCH CENTRE, CHELMSFORD, U.K.- Publication:
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Advances in Space Research
- Pub Date:
- 1990
- DOI:
- 10.1016/0273-1177(90)90361-3
- Bibcode:
- 1990AdSpR..10c.311M