ISSN Online: 2379-1748
7th Thermal and Fluids Engineering Conference (TFEC)
SJR: 0.152 SNIP: 0.14 CiteScore™:: 0.5
DESIGN AND EXPERIMENTAL EVALUATION OF HYDRAULIC LIFT-OFF SEAL FOR LOX-KEROSENE STAGED COMBUSTION CYCLE ENGINE TURBOPUMP
LPSC has taken up the development of a LOX-kerosene engine working on staged combustion cycle. Towards the same, subsystem level tests are in progress for realization of the main turbopump. To facilitate multiple re-uses, the turbopump is configured with dynamic sealing systems offering minimal friction and wear during operation. The design and testing aspects of one such sealing system, with a negative balance ratio and employing a lift-off mechanism actuated by hydraulic means, are discussed in the present paper. The seal provides leak tightness during the static, non-operational phase of the turbopump and prevents leakage of LOX into the thrust chamber. A mathematical model is formulated for simulating the seal operation and fluid flow through a dynamic test rig. The model has been validated using experimental data and reasonable conformance has been established. Development and qualification tests of the seal were carried out in water medium (instead of liquid oxygen) in the dynamic test rig by simulating its functioning as in actual turbopump. To assess the effect of multiple restarts, adequate seal operation cycles have been demonstrated at the rated speed. Subsequent to completion of test campaign, inspection of the critical dimensions of the seal is performed to assess the seal wear. Experiments demonstrated satisfactory seal lift-off performance and minimal wear of the sealing face for more than 25 start-stops of the turbopump.