• Journal of Aerospace System Engineering
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• v.14 no.5
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• pp.100-106
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• 2020

Turbopumps for liquid rocket engines are exposed to various cavitation instabilities under their operating conditions. The instabilities affect the stability of the turbopumps. To make sure of the stability of the turbopump of KSLV-II, the present work examined the characteristics of the cavitation instabilities during the turbopump assembly test. In the test, the LOx pump was operated under super-synchronous rotating cavitation and attached to uneven cavitation. In the vibration analysis of the fuel pump, the characteristic frequency by the super-synchronous cavitation of the LOx pump was clearly shown.

• Journal of the Korean Society of Propulsion Engineers
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• v.2 no.2
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• pp.64-73
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• 1998

In twin spool aero-engine, there may be a S shaped annular duct between high pressure and low pressure spools. The flow passing this S shaped duct experiences the flow acceleration and deceleration due to the convex and concave surface of the duct as well as the increase of blockage according to the boundary layer growth along the surfaces. So, the high pressure compressor which is located behind the S shaped duct is influenced by the non-uniform flow field generated by the geometry of inlet duct. To study the influence of the S shaped duct on the centrifugal stage, performance tests were implemented for the compressor with straight cylindrical inlet duct and with S shaped inlet duct, respectively. The test results showed that the performance, such as pressure ratio and efficiency, of the compressor with S shaped duct was worse than that of the compressor with cylindrical duct. And the compressor with S shaped duct had reduced maximum flow rate around design speed. To investigate the cause of performance degradation, flow anlaysis was performed for the impeller in front of which is located S shaped annular duct. The result of CFD showed the strong acceleration of the flow in the axial direction around the inducer tip region which caused the increase of relative mach number and the decrease of incidence angle of the flow.