| Research Abstract |
The failure of launching the H II Rocket of 1999 was caused by destruction of turbo-pump due to cavitation occurring in inducer of the pump. Inducer of a rocket pump operates in heavy shear flow due to the walls of casing and boss, and further operates in partially cavitating condition.
From these circumstances, hydrodynamic characteristics are analyzed about a partially cavitating cascade which is placed in shear flow between parallel plane walls.
An equation of motion with respect to disturbance pressure is transformed into two problems by separation of variables. One of them is that of spanwise direction and the other is that of sectional plane of a hydrofoil in cascade.
For the problem of the spanwise direction, an existing analytical solution is adopted. The problem of sectional plane of the hydrofoil in cascade is reduced to a simultaneous integral equation with respect to singularity distributions and is solved by using the analytical method previously proposed by the author for the three dimensional cascade without cavitation.
These two kinds of solutions corresponding to individual eigenvalues are combined linearly, and expression of cascade and cavity characteristics are obtained.
Numerical calculations are carried out to clarify the characteristics, especially cavity free stream line form, for the same cascade condition and cavity length as the real launching condition of H II A Rocket developed newly.
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