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 test of the 75ton class turbopump turbine was performed. Using the measured turbine power characteristics in the wide-range operational conditions, variations of nozzle velocity ratio, total pressure loss, and relative flow angle to the pressure ratios and rotational speeds are quantified. Efficiency and nozzle exit pressure behavior was also investigated and compared with 30ton turbopump turbine data. A rotor blade was redesigned based on the test results and CFD analysis.

Investigation on the Performance Characteristics of the 75ton Class Turbopump Turbine

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

The effect of tip clearance on the performance of a supersonic impulse turbine was investigated experimentally. Test was performed using high pressure air in wide ranges of pressure ratio and rotational speeds. Test revealed that efficiency gradient of the subject turbine at a reference test point was a very low value of 0.05. Turbine efficiency was varied non-linearly with respect to tip clearance. It has been found that efficiency gradient is proportional to the cube of rotational speed at a fixed turbine pressure ratio. It also has been found that efficiency gradient shows its minimum at a reference test pressure ratio irrespective of rotational speeds.

https://www.koreascience.kr:443/article/CFKO200809651046706.pdf

Pyun-Goo Park

Papers

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

Performance Test of a 7 tonf Liquid Rocket Engine Turbopump

Investigation on the Performance Characteristics of the 75ton Class Turbopump Turbine

Performance Test of a 75-tonf Rocket Engine Turbopump

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