Abstract
Steady incompressible flow around a circular cylinder in an
external magnetic field that is aligned with fluid flow direction
is studied for Re (Reynolds number) up to 40 and the
interaction parameter in the range 0≤N≤15 (or 0≤M≤30), where M is the Hartmann number related to N by the
relation M=2NRe, using finite difference method.
The pressure-Poisson equation is solved to find pressure fields in
the flow region. The multigrid method with defect correction
technique is used to achieve the second-order accurate solution of
complete nonlinear Navier-Stokes equations. It is found that the
boundary layer separation at rear stagnation point for Re=10
is suppressed completely when N<1 and it started growing again
when N≥9. For Re=20 and 40, the suppression is not
complete and in addition to that the rear separation bubble
started increasing when N≥3. The drag coefficient decreases
for low values of N(<0.1) and then increases with increase
of N. The pressure drag coefficient, total drag coefficient, and
pressure at rear stagnation point vary with N. It is also found that the upstream and downstream pressures on the surface of
the cylinder increase for low values of N(<0.1) and rear pressure inversion occurs with further increase of N. These results are in agreement with experimental findings.