Analysis and Prediction of Radiation Belt Environment for the ESA Integral Satellite
- Paper number
IAC-04-U.6.-IAA.4.9.3.03
- Author
Mr. Ronnie Lindberg, Sweden
- Year
2004
- Abstract
In the present work, computations of hypersonic magnetohydrodynamic (MHD) laminar flow over a 3D blunt have been undertaken. Aero-thermal reducing effects by applied magnetic field were concerned. It offers a potential alternative to conventional flow control technique without any modify on surface of space vehicle.
MHD equations upon low magnetic Reynolds number approximation were solved by finite volume method, second-order OC-TVD spatial scheme and LU-SGS algorithm. Viscous term was centrally differenced. The code was firstly validated by computations for classical Hartmann flow. Computed results show full developed steady Hartmann flow. The velocity profiles make a good agreement with analytical solution.
Subsequently, MHD flow over a hemisphere, with a free stream Mach numberMa=5, was investigated numerically. Electric conductivity is idealized. A magnetic dipole field lies in the centre of the hemisphere. Magnetic field and electric conductivity is expressed by magnetic interaction parameter Q from 0 to 6. Because there is high requirement on mesh used in aero-thermal calculation, firstly three meshes with different Remesh (Reynolds number in normal direction of wall) were considered to examine mesh effect. Results exhibit the mesh of Remesh=4 is competent for simulation.
Simulations for various Q were carried out with mesh of Remesh=4. It show that streamline in the vicinity of stagnation point is deflexed by magnetic force severely. There is a dramatic increase on Shock standoff distance (80 percent increase from Q=0 to Q=6). In Q=0 the computational result makes a good agreement with PoggieGaitonde simulation. The distance from Bush analysis solution is lower than other results, but the variation trend is consistent. Moreover, results show obvious reduction on wall heat transfer in the vicinity of the stagnation point(26 percent reduction from Q=0 to Q=6), but a slight variation on wall pressure. Heat transfer results were also compared with Bush theoretical model.
For free stream of higher Mach number Ma=15, Effects by various electric conductivities were studied. Local electric conductivity is solved by chemical equilibrium empirical relations. It is observed heat transfer reduction is less than that of uniform electric conductivities. The variation mechanism was then analyzed.
- Abstract document
- Manuscript document
IAC-04-U.6.-IAA.4.9.3.03.pdf (🔒 authorized access only).
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