Investigation on the Pump Suction Performance and Thermodynamic Effects

2020 ◽  
Author(s):  
Eunhwan Jeong ◽  
Byung Yun Kang ◽  
Soon Sam Hong ◽  
Dae Jin Kim ◽  
Chang Ho Choi
Keyword(s):  
Performance Test ◽  
Rocket Engine ◽  
Cavitation Number ◽  
Liquid Oxygen ◽  
Inlet Temperature ◽  
Test Results ◽  
Pump Head ◽  
Thermodynamic Effects ◽  
Critical Cavitation ◽  
Suction Performance

Abstract The thermodynamic effects on the suction performance of a liquid oxygen (LOX) pump, observed during liquid rocket engine combustion tests, were investigated. Owing to the pump rotational speed and inlet pressure variation in the short duration of the engine starting, LOX pump head drops occurred occasionally depending on the initial pump inlet condition. Because the engine tests were performed at various inlet temperature and pressure settings of the LOX pump, the resulting suction performance behaviors of the LOX pump were varied. The critical cavitation number, at which the pump head drops 3%, was considered as the main parameter for representing the pump suction performance. The suction performance behaviors shown in the engine tests were investigated based on the classical theory of thermodynamic effects on cavitation. The LOX pump component test results in water, the LOX pump assembly suction performance test results in liquid nitrogen, and the J-2 LOX pump test results available in the open literature were used in the analysis and comparison. It was found that the critical cavitation number ratio of a pump could be expressed as a function of the thermodynamic parameter Σ*. For a given LOX pump flow condition, Stepanoff’s B-factor was almost constant at the specified head drop condition; as a result, Brennen’s time scale ratio βwas not constant but varying with Σ*. The argument of the geometrical similarity of pump cavitation at the critical condition of the pump head drop was addressed in conjunction with the constancy of Stepanoff B-factor.

Critical Suction Peformance Test of Turbopump Assembly for a Liquid-Propellant Rocket Engine

2018 ◽  
Author(s):  
Hang Gi Lee ◽  
Ju Hyun Shin ◽  
Suk Hwan Yoon ◽  
Dae Jin Kim ◽  
Jun Hwan Bae ◽  
...  
Keyword(s):  
Liquid Nitrogen ◽  
Performance Test ◽  
Rocket Engine ◽  
Lightweight Design ◽  
Cavitation Number ◽  
Inlet Pressure ◽  
Liquid Oxygen ◽  
Pump Failure ◽  
Critical Cavitation ◽  
Suction Performance

This study investigates the behavior of a turbopump assembly during critical cavitation of the propellant pumps in the upper rocket engine of the Korea Space Launch Vehicle-II. Turbopumps operate under conditions involving low pressure at the pump inlet and high rotational speeds to allow for a lightweight design. This severe environment can easily cause cavitation to occur in the pump. This cavitation can then cause the pump operation to fail. As the cavitation number in the pump decreases below the critical point, the pump fails to operate. There is concern regarding the behavior of the turbopump assembly arising from pump failure due to cavitation. It is necessary to verify the problems that may occur if the turbopump assembly operates under extreme conditions, such like the critical cavitation. This study performed tests to investigate the breakdown of pumps in the turbopump assembly. Tests were conducted with liquid nitrogen, water, and high-pressure air instead of the mediums used during actual operation of liquid oxygen, kerosene, and hot gas. The turbopump was tested at the design point of 27,000 rpm, while the inlet pressure of each pump was controlled to approach the critical cavitation number. The turbine power output was maintained during the tests. The results show that the breakdown point of the oxidizer pump using liquid nitrogen, which is a cryogenic medium, occurred at a lower cavitation number than during an individual component suction performance test using water. The fuel pump using water, meanwhile, experiences breakdown at similar cavitation numbers in both tests. As the breakdown of the pump occurs, the power required by that pump decreases, and the rotational speed of the turbopump increases. Compared with individual pump suction performance tests, this breakdown test can be used to determine the limit of the propellant inlet pressure of the turbopump and to characterize the behavior of the turbopump assembly when a breakdown occurs. Vibrations were also analyzed for tests at a high cavitation number and at the critical cavitation number. The vibration increased with breakdown and notable frequencies were analyzed.

Inducer Design Optimization to Improve its Suction Performance

2019 ◽  
Author(s):  
Yushi Nakamura ◽  
Marek Lubieniecki ◽  
Kentarou Hayashi ◽  
Yutaka Kawata ◽  
Masahiro Miyabe ◽  
...  
Keyword(s):  
Response Surface ◽  
Design Space ◽  
Cavitation Number ◽  
Design Parameters ◽  
Baseline Design ◽  
Starting Point ◽  
Blade Shape ◽  
Critical Cavitation ◽  
Suction Performance ◽  
The Relationship

Abstract The purpose of this paper is to present optimization method of an inducer blade shape to improve its suction performance and clarify the relationship between pump performance and design parameters. In order to conduct the optimization process a response surface based optimization framework was established. Baseline was designed in previous research [1]. The inducers were 3Dprinted in ABS plastic and their wetted and cavitating characteristics were measured. It was confirmed that the optimized inducer can maintain its wetted performance at lower cavitation numbers. A response surface is a mathematical model that approximates the relationship between the input parameters and the objective function from a finite number of learning points within the design space. The design space was defined by four parameters: sweep angle, sweep radius, incidence angle and blade solidity at the tip that controlled the blade shape. The performance of each design was evaluated with a CFD simulation established in a commercial solver. The optimization goal was to minimize the critical cavitation number that corresponds to a 5% drop of pressure increase through the pump due to cavitation. A starting point of the optimization was the industrial pump designed by a Japanese company Teral [1]. The results of the numerical optimization show that the critical cavitation number was decreased by 17.6% with respect to the baseline design. In the experimental results, an average improvement of 15.4% was achieved.

System performance tests and start transient analysis of a liquid rocket engine turbopump

2012 ◽  
Vol 227 (3) ◽  
pp. 470-480
Author(s):  
Soon-Sam Hong ◽  
Dae-Jin Kim ◽  
Jin-Sun Kim ◽  
Jinhan Kim
Keyword(s):  
Rocket Engine ◽  
Hydrogen Gas ◽  
Liquid Oxygen ◽  
Test Results ◽  
Gas Generator ◽  
Fuel Pump ◽  
Performance Requirements ◽  
Component Test ◽  
Liquid Rocket ◽  
Model Fluids

This article describes a series of development tests of a turbopump, which can be applied to a gas generator cycle rocket engine with liquid oxygen and kerosene propellants. A turbine drives both an oxidizer pump and a fuel pump in the turbopump assembly. In the tests, liquid oxygen and kerosene are supplied to the oxidizer pump and the fuel pump, respectively, while either cold hydrogen gas or hot gas from the gas generator is supplied to the turbine. The turbopump is operated reliably at both on-design and off-design conditions, meeting all the performance requirements. The test results are compared with those of the turbopump component tests, where model fluids are used, that is, water for the oxidizer pump and the fuel pump, and cold air for the turbine. The turbopump tests results agree well with the turbopump component test results. The speed buildup of the turbopump at start period is calculated when pressurized gas is used to initially spin the turbine. A differential equation which represents the torque balance between the turbine and the pumps is solved. The calculation shows a good agreement with the test result. When the mechanical loss of the turbopump is considered, a better estimation is obtained.

scholarly journals Study on inducer and impeller of a centrifugal pump for a rocket engine turbopump

2012 ◽  
Vol 227 (2) ◽  
pp. 311-319 ◽  
Author(s):  
Soon-Sam Hong ◽  
Dae-Jin Kim ◽  
Jin-Sun Kim ◽  
Chang-Ho Choi ◽  
Jinhan Kim
Keyword(s):  
Centrifugal Pump ◽  
Performance Test ◽  
Rocket Engine ◽  
Water Environment ◽  
Centrifugal Impeller ◽  
Liquid Rocket Engine ◽  
Cavitation Performance ◽  
Liquid Rocket ◽  
Critical Cavitation ◽  
Flow Interference

A hydraulic performance test is conducted for a fuel pump of a liquid rocket engine turbopump. The pump driven by an electric motor is tested in a water environment. Experimental results indicate that the inducer has a negligible effect on the head and efficiency of the pump but a significant effect on the cavitation performance. Additionally, an autonomous inducer test is carried out to investigate the effect of the inducer on the pump performance in more detail, and it is found out that the pump reaches a critical cavitation point when the inducer head is dropped by 55%. A reduction of required net positive suction head of the centrifugal pump by attachment of an inducer is also calculated considering the flow interference between the inducer and the centrifugal impeller, and it is found that the calculation shows a reasonable agreement with the test.

scholarly journals Influence of the Blade Number on Inducer Cavitating Behavior

2009 ◽  
Author(s):  
O. Coutier-Delgosha ◽  
G. Caignaert ◽  
G. Bois ◽  
J.-B. Leroux ◽  
Patrick Olivier ◽  
...  
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Rocket Engine ◽  
Cavitation Number ◽  
Design Flow ◽  
Flow Rates ◽  
Blade Number ◽  
Radial Forces ◽  
Critical Cavitation

Effects of the blade number on the performance of a rocket engine turbopump inducer are investigated in the present paper. For that purpose, two inducers characterized by three blades and five blades respectively were manufactured and tested experimentally. The two inducers were designed on the basis of identical design flow rate, and identical pressure elevation at nominal flow rate. The first part of the study focuses on the steady behavior of the inducers in cavitating conditions: evolutions of performance, torque, mass flow rate, and amplitude of radial forces on the shaft according to the inlet pressure are considered. Several flow rates and rotation speeds are investigated. Significant differences between the inducers are obtained concerning the critical cavitation number, the amplitude of the radial forces, and the organization of cavitation in the machinery. Cavitation instabilities are investigated in the second part of the study. Various flow patterns are detected according to the mass flow rate and the cavitation number.

scholarly journals Influence of the Blade Number on Inducer Cavitating Behavior

2012 ◽  
Vol 134 (8) ◽  
Author(s):  
O. Coutier-Delgosha ◽  
G. Caignaert ◽  
G. Bois ◽  
J.-B. Leroux
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Rocket Engine ◽  
Cavitation Number ◽  
Design Flow ◽  
Flow Rates ◽  
Blade Number ◽  
Radial Forces ◽  
Critical Cavitation

Effects of the blade number on the performance of a rocket engine turbopump inducer are investigated in the present paper. For that purpose, two inducers characterized by three blades and five blades, respectively, were manufactured and tested experimentally. The two inducers were designed on the basis of identical design flow rate and identical pressure elevation at nominal flow rate. The first part of the study focuses on the steady behavior of the inducers in cavitating conditions: evolutions of performance, torque, mass flow rate, and amplitude of radial forces on the shaft according to the inlet pressure are considered. Several flow rates and rotation speeds are investigated. Significant differences between the inducers are obtained concerning the critical cavitation number, the amplitude of the radial forces, and the organization of cavitation in the machinery. Cavitation instabilities are investigated in the second part of the study. Various flow patterns are detected according to the mass flow rate and the cavitation number.

PENGARUH MODEL PEMBELAJARAN KELILING KELOMPOK (ROUND CLUB) TERHADAP KETERAMPILAN MENULIS LAPORAN PERJALANAN SISWA KELAS V SDN 01 NAGARI BUKIK SIKUMPA

2020 ◽  
Author(s):  
Wirda Linda
Keyword(s):  
Standard Deviation ◽  
Performance Test ◽  
Writing Skills ◽  
Learning Model ◽  
Homogeneity Test ◽  
Test Results ◽  
Class V ◽  
Average Value ◽  
Normality Test ◽  
Lecture Method

This research is motivated by the low desire of students in writing travel reports. The lack of students' knowledge of the report concept, the lack of students' knowledge of the 5W + 1H report points of good and correct language, the lack of students' knowledge of the spatial, time and topic pattern and not yet reached KKM 75. The method used by the teacher has not been interesting, lecture method. The purpose of this study is to describe the skills of writing travel reports by using Round Club learning model which is viewed from the aspect of understanding the report concept, the use of 5W +1H report points, the spatial, time, and topic pattern.The population of this study is the students of class V Lessons Year 2017/2018 which amounted to 2 classes with the number 80. The sample of research as much as two classes taken by the sample of propotional.Class V.1 as experimental class and class V.2 as control class. The research instrument used is performance test. Provide an assessment by specifying the subject of the 5W + 1H report, as well as the spatial, time and topic pattern. Data were analyzed by 't' test by first testing normality, homogeneity, and hypothesis testing.The results showed that the average control class 68 with more than enough qualifications with standard deviation 16.96. 83 experimental class with good qualification and standard deviation of 15.42 and there is a significant influence on the result of writing skill of class V SDN 01 Nagari Bukik SikumpaSubdistrict, Lima Puluh Kota. This is evidenced by the average value of writing skills in the experiment class higher than the average value in the control class. Normality test results indicate that the two sample classes of  Lo  values in the control class -0.2141 are smaller than the normal 0.190 Lt distributed. Homogeneity test results that the variation of this study is homogeneous at a real level of 0.05, because Ftable 2.16 > Fhitung 1.21 and the results of data analysis then obtained = 2.78 > 1.70 t table, so H0 rejected and H1 accepted. It can be concluded that there is Influence. Using  Learning  Model of Student Group Writing  Skills Travel Report of students of class V SDN 01 Nagari Bukik Sikumpa Subdistrict, Kabupaten Lima Puluh Kota.KeyWords: model pembelajaran round club, menulis laporan perjalanan.

Physical and performance characteristics related to starter status, position, and division in Japanese collegiate American-football players

2021 ◽  
pp. 1-8
Author(s):  
Junta Iguchi ◽  
Minoru Matsunami ◽  
Tatsuya Hojo ◽  
Yoshihiko Fujisawa ◽  
Kenji Kuzuhara ◽  
...  
Keyword(s):  
Performance Test ◽  
Vertical Jump ◽  
American Football ◽  
Football Players ◽  
Jump Height ◽  
Test Results ◽  
Repetition Maximum ◽  
Vertical Jump Height ◽  
Division 1 ◽  
And Performance

BACKGROUND: Few studies have investigated the variations in body composition and performance in Japanese collegiate American-football players. OBJECTIVE: To clarify what characterizes competitors at the highest levels – in the top division or on the starting lineup – we compared players’ body compositions and performance test results. METHODS: This study included 172 players. Each player’s body composition and performance (one-repetition maximum bench press, one-repetition maximum back squat, and vertical jump height) were measured; power was estimated from vertical jump height and body weight. Players were compared according to status (starter vs. non-starter), position (skill vs. linemen), and division (1 vs. 2). Regression analysis was performed to determine characteristics for being a starter. RESULTS: Players in higher divisions and who were starters were stronger and had more power, greater body size, and better performance test results. Players in skill positions were relatively stronger than those in linemen positions. Vertical jump height was a significant predictor of being a starter in Division 1. CONCLUSION: Power and vertical jump may be a deciding factor for playing as a starter or in a higher division.

Measurements of Rotordynamic Coefficients of Hybrid Bearings With (a) a Plugged Orifice, and (b) a Worn Land Surface

2002 ◽  
Vol 124 (2) ◽  
pp. 363-368 ◽  
Author(s):  
F. Laurant ◽  
D. W. Childs
Keyword(s):  
Test Data ◽  
Land Surface ◽  
Rocket Engine ◽  
Liquid Rocket Engine ◽  
Test Results ◽  
Rotordynamic Coefficients ◽  
Hybrid Bearing ◽  
Liquid Rocket

Test results are presented for the rotordynamic coefficients of a hybrid bearing that is representative of bearings for liquid-rocket-engine turbopump applications. The bearing is tested in the following two degraded conditions: (a) one of five orifices plugged, and (b) a locally enlarged clearance to simulate a worn condition. Test data are presented at 24,600 rpm, with supply pressures of 4.0, 5.5, and 7.0 MPa, and eccentricity ratios from 0.1 to 0.5 in 0.1 increments. Overall, the results suggest that neither a single plugged orifice nor significant wear on the bearing land will “disable” a well-designed hybrid bearing. These results do not speak to multiple plugged orifices and are not an endorsement for operations without filters to prevent plugging orifices.

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