Performance assessment of electrically driven pump-fed LOX/kerosene cycle rocket engine: Comparison with gas generator cycle

Experimental and numerical investigation of design optimization of a partial admitted supersonic turbine

Partial admission effect on the performance and vibration of a supersonic impulse turbine

Purpose



– This study aims to presenting an empirical model for partially admitted turbine efficiency. When the design mass-flow rate is too small that a normal full-admission design would give very-small blade height, it may be advantageous to use partial admission. The losses due to partial admission with long blades may be less than the losses due to leakage and low Reynolds-number of the full-admission turbines with short blades. The turbine efficiency is highly dependent on the degree of partial admission. The empirical model of turbine efficiency is necessary for simulation and analysis of dynamic performances of the turbine system. In this work, appropriate empirical loss correlations are introduced and a proper model is proposed for turbine efficiency. 




Design/methodology/approach



– Experimental and numerical tests are conducted to evaluate the proposed model and the results are compared with the results of existing models. In this work, the effect of nozzles overlapping on the flow pattern is emphasized. Therefore, various models with different degrees of overlapping are simulated and their effects on the turbine efficiency are subsequently evaluated. 




Findings



– A suitable cubic polynomial expression for small axial supersonic turbine efficiency in experiments is suggested. The overlapping nozzles cause change in the flow pattern and the entropy distribution. Therefore, any change in the degree of overlapping of nozzles changes the efficiency of the turbine. 




Research limitations/implications



– In this work, time-consuming numerous experimental and numerical tests of the turbine are required. 




Practical implications



– Implication of a proper formula for a partially admitted turbine may result in enhanced prediction and dynamic performance evaluation of the test turbine. 




Originality/value



– A proper empirical model for a partially admitted supersonic turbine is introduced. This model is suitable for one blocked partially admitted turbine with Mach number between 1.2 and 1.8.

An empirical model for partially admitted turbine efficiency

Secondary and tip clearance flows in axial turbines: Heat transfer aspects

An experimental investigation of the effect of tip clearance on the performance of a shrouded supersonic impulse turbine was performed in this study. A single-staged axial flow impulse turbine designed to have a rotor inlet relative Mach number of 1.7 was used for the experiment. Turbine efficiency was measured at various settings of tip clearances, rotational speeds, and turbine pressure ratios to observe the characteristics of the efficiency gradient. The overall efficiency of the supersonic impulse turbine was largely affected by rotational speed. For a fixed rotational speed, local maximum efficiency was found near a turbine pressure ratio at which the turbine nozzle was fully expanded. At a reference test point, the linearly estimated efficiency gradient was 0.09. However, efficiency variation with respect to tip clearance was nonlinear, and relatively larger efficiency gradients were found at small tip clearances and high rotational speeds. It has been found that the efficiency gradient varies linearly with the cube of rotational speed and shows its minimum value near the reference turbine pressure ratio.

Tip Clearance Effect on the Performance of a Shrouded Supersonic Impulse Turbine

Performance tests of a turbopump for the developing 7-tonf li quid rocket engine were conducted The performance of turbopump components and their power matchin g were measured and examined firstly under the LN2 and water environment In the real prope llant(LOX and kerosene) environment tests, design and off-design performances of turbopump were ful ly verified During the off-design tests, turbopump running time was set the same as engine operat ing time and pump inlet pressure were set lower than nominal operating value in order to investigate pump suction capability It have been verified that subject turbopump satisfies required performance - flow rate, head, suction performance and operational time - in the operating regime of d eveloping liquid rocket engine초 록 7톤급 액체로켓엔진용 터보펌프 개발 시제에 대한 조립체 성능시험이 수행되었다 LN2와 물이 적용된 상사매질 조립체 시험을 통해 터보펌프 단품 간 출력 매칭 및 조립체 레벨에서의 수력/공력 성능 검증이 선행되었으며 LOX와 케로신의 실제 운용 환경의 실매질 시험에서는 터보펌프의 설계점, 탈설계점 성능 검증시험이 이루어졌다 탈설계시험은 엔진의 운용시간을 적용하여 이루어졌으며 펌프의 흡입성능 검증을 병행하였다 개발된 7톤급 액체로켓용 터보펌프는 엔진운용영역에서 유량, 양정, 흡입 성능, 그리고 운용시간의 요구규격을 만족시키는 것으로 확인되었다Key Words:Liquid Rocket Engine(액체로켓엔진), Turbopump(터보펌프), Performance Test(성능시험), Kerosene(케로신), LOX(액체산소)Received 27 December 2014 / Revised 8 March 2015 / Accepted 13 March 2015

Performance Test of a 7 tonf Liquid Rocket Engine Turbopump

Performance tests of a 75-tonf liquid rocket engine turbopump were conducted. The performance of sub-components - two pumps and a turbine - and their power matching were measured and examined firstly near the design speed under the LN2 and kerosene enviro nment. In the real propellant - LOX and kerosene - environment tests, design and off-design performance of turbopump were fully verified in regime of the rocket engine operation. During the off-design performance tests, turbopump running time was set longer than the engine operating time to verify the pump operability and set the pump inlet pressure close to design NPSHr to investigate pump suctio n capability in parallel. It has been found that developed-turbopump satisfied all of the engine required performances.초 록 75톤급 액체로켓엔진용 터보펌프 개발 시제에 대한 조립체 성능시험이 터보펌프 실매질 시험설비에서 수행되었다. LN2와 케로신을 적용한 첫 시험에서는 터보펌프 구성품들의 조립체 상태에서의 수력/공력 성능 및 출력 매칭 점검이 설계회전수 근방에서 이루어 졌으며 LOX와 케로신을 적용한 실매질 시험에서는 터보펌프의 설계성능 및 엔진운용영역 탈설계 성능 검증이 이루어졌다. 탈설계시험의 경우, 내구성 검증을 위해 엔진의 운용시간을 초과하여 터보펌프가 운용되었으며 펌프입구압력을 설계 요구유효흡입양정(NPSHr)에 가깝게 설정하여 흡입성능 검증을 병행하였다. 개발된 75톤급 액체로켓용 터보펌프는 성능, 운용시간의 엔진 요구규격을 만족시키는 것으로 확인되었다.Key Words:Liquid Rocket Engine(액체로켓엔진), Turbopump(터보펌프), Performance Test(성능시험), Kerosene(케로신), LOX(액체산소)Received 2 December 2015 / Revised 29 February 2016 / Accepted 7 March 2016

Performance Test of a 75-tonf Rocket Engine Turbopump

This paper highlights the performance of an impulse turbine which is a part of turbopump in a liquid rocket first stage engine. The turbopump,...

https://www.koreascience.or.kr:443/article/JAKO201630762633289.pdf

Turbine Performance Experiments for the Turbopump of a Liquid Rocket Engine

Turbine rotor-pyrostarter coupled test was performed for the verification of thermo-structural suitability of a turbopump turbine. Newly developed solid propellant and design concept were used in pyrostarter development. In case of turbine rotor, rotor config uration modification and post EDM machining process are adopted in rotor manufacturing respective ly for the thermal stress relief and the surface integrity improvement on the blade surfaces. In the tes t, combustion gas of pyrostarter was directly ejected from the nozzles and impinged on the stationar y turbine rotor specimen through the identically shaped flow passage of turbopump. Three kind of thermal load - design to extreme condition - test were performed and no damages were found on the turbine rotor specimens. 초 록 터보펌프 터빈로터의 열구조적 적합성 검증을 위한 터빈로터-파이로시동기 연계시험을 수행하였다. 새로운 추진제를 적용한 파이로시동기와 열응력 경감 설계 및 터빈 동익 표면 건전성 향상을 위한 후가공 공정이 적용된 터빈로터시편이 시험에 사용되었다. 시험은 75톤급 엔진시동을 위한 파이로 시동기의 연소가스를 터보펌프 터빈로터와 동일한 형상의 시편에 분사하는 방식으로 이루어졌다. 터빈에 가해지는 열 부하는 운용 설계점에서 극한 조건까지 세 종류로 구분하여 시험을 진행하였으며 모든 시험에서 터빈로터의 손상은 발견되지 않았다.Key Words: Turbopump(터보펌프), Turbine(터빈), Pyrostarter(파이로시동기), 연계시험(Coupled-test)Received 7 June 2013 / Revised 23 December 2013 / Accepted 2 J anuary 2014

Hang-Gi Lee

Papers

Tip Clearance Effect on the Performance of a Shrouded Supersonic Impulse Turbine

Performance Test of a 7 tonf Liquid Rocket Engine Turbopump

Performance Test of a 75-tonf Rocket Engine Turbopump

Turbine Performance Experiments for the Turbopump of a Liquid Rocket Engine

Turbine Rotor-Pyrostarter Coupled Test for the Verification of Thermo-Structural Suitability of a Turbopump Turbine