Performance of Small High Speed Cryogenic Pumps

1985 ◽  
Vol 107 (2) ◽  
pp. 197-203 ◽  
Author(s):  
Kenjiro Kamijo ◽  
Kunio Hirata
Keyword(s):  
High Speed ◽  
Rocket Engine ◽  
Pump Efficiency ◽  
Test Results ◽  
Flow Rates ◽  
High Head ◽  
Design Characteristics ◽  
Liquid Rocket ◽  
Reported Data ◽  
The Relationship

Several small cryogenic pumps for a liquid rocket engine have been made and tested. These pumps have a small impeller and are characterized by high speed and high head. The main design characteristics of these pumps are as follows: stage specific speeds of from 0.0319 to 0.0766, flow rates from 0.016 to 0.0525 m3/s, pressure rises from 4.9 to 26 MPa, rotational speeds from 16,500 to 80,000 rpm, and impeller diameters from 0.083 to 0.146 m. These pumps, when tested, showed higher efficiency even in the range of small stage specific speeds than any previously reported data on other pumps. This tendency was particularly striking with the two-stage pumps. With regard to pump efficiency measurement, it was made clear that adiabatic efficiency was utilizable for the present cryogenic pumps. The relationship between the adiabatic efficiency and ordinary efficiency was also confirmed by a brief calculation and test results.

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.

Characterization of Rotating Cavitation in a High Speed Inducer of Liquid Rocket Engine

2011 ◽  
Vol 320 ◽  
pp. 196-201
Author(s):  
Fei Tang ◽  
Li Jia Wen
Keyword(s):  
High Speed ◽  
High Performance ◽  
Rocket Engine ◽  
Liquid Rocket Engine ◽  
Blade Surface ◽  
Cavitation Phenomenon ◽  
Flow Fluctuations ◽  
Blade Cascade ◽  
Liquid Rocket

Rotating cavitation is one of the most important problems in the development of modern high performance rocket pump inducers. In this paper, a numerical simulation of rotating cavitation phenomenon in a 2D blade cascade of liquid rocket engine inducer was carried out using a mixture model based on Rayleigh-Plesset equation. The purpose is to investigate the characterization of rotating cavitation in a high speed inducer. The results show that when sub-synchronous rotating cavitation occurs, the speed for the length of the blade surface cavitation is lower than the speed frequency of rotation shaft with the same direction. The external aspect is that the pressure at the upstream of blades changes synchronous. Thus, the generation of sub-synchronous rotating cavitation is closely related to the changes of flow angel which caused by the flow fluctuations. Hence, elimination of the flow rate redistribution among the flow channel can effectively suppress the occurrence of this phenomenon.

Simulation of hot high-speed yielding of intermetallic titanium alloy VTI-4 under conditions of high-speed loading

2020 ◽  
Vol 0 (12) ◽  
pp. 10-16
Author(s):  
V.V. Avtaev ◽  
◽  
D. V. Grinevich ◽  
A. V. Zavodov
Keyword(s):  
Finite Element ◽  
Titanium Alloy ◽  
Strain Rate ◽  
Finite Element Simulation ◽  
Modulus Of Elasticity ◽  
High Speed ◽  
Residual Deformation ◽  
Test Results ◽  
Element Simulation ◽  
The Relationship

Yielding tests of VTI-4 alloy specimens have been carried out at temperature 1010 °C under conditions of high-speed loading. Based on the test results the modulus of elasticity as well as axial and radial residual deformation values in the end and central zones for each loading stage were determined. Fitting criteria for finite element simulation and the experiment are proposed with tracing VTI-4 alloy diagram deformation at temperature 1010 °C and strain rate of 2.5 sec–1. As a result of finite element simulation the relationship between the material structures obtained during high-speed yielding and the deflected modes in different zones was determined.

Entropy production analysis for the clocking effect between inducer and impeller in a high-speed centrifugal pump

2019 ◽  
Vol 233 (15) ◽  
pp. 5302-5315 ◽  
Author(s):  
Baofeng Yang ◽  
Bin Li ◽  
Hui Chen ◽  
Zhanyi Liu
Keyword(s):  
Entropy Production ◽  
Centrifugal Pump ◽  
High Speed ◽  
Rocket Engine ◽  
Leading Edge ◽  
Entropy Production Rate ◽  
Pump Efficiency ◽  
Impeller Blade ◽  
Turbulent Dissipation ◽  
Production Analysis

The clocking effect between the inducer and the impeller has a certain impact on the performance of the high-speed centrifugal pump, which however, is often ignored by designers. In the present study, three-dimensional numerical simulation based on Reynolds-averaged Navier–Stokes method is adopted to evaluate the influence of this clocking effect on the performance of a full-scale liquid rocket engine oxygen turbopump. A novel entropy production method with the correction of wall effects was introduced to evaluate the energy loss generated in the pump and to clarify the formation mechanism of this clocking effect from the perspective of the second law of thermodynamics. Results show that the best performance is captured when the relative circumferential angle between the inducer blade trailing edge and the impeller blade leading edge was set as 0° and the maximum difference in pump efficiency is approximately 1.5% at different clocking positions. The entropy production analysis of each component of the pump reveals that the clocking effect on the pump performance mainly originates from the turbulent dissipation in the impeller and the diffuser. The study of the local entropy production rate and the streamline distributions shows that the formation of this clocking effect is owing to the different extent of the separation vortices in the impeller passage near the shroud and the impeller blade wake in the diffuser inlet as well as the backflow vortices in the diffuser blade passage near the volute tongue.

A study of anti-cavitation properties of propellant-feeding systems of oxygen/hydrogen engines operating on boiling hydrogen

2020 ◽  
pp. 35-44
Author(s):  
Yury V. DEMIYANENKO ◽  
Yury P. KOSMACHEV ◽  
Aleksandr A. AFANASYEV
Keyword(s):  
Rocket Engine ◽  
Test Results ◽  
Stationary Model ◽  
Math Model ◽  
Flow Rates ◽  
Test Setup ◽  
Flow Simulations ◽  
Hydrogen Engines ◽  
Setup Operation ◽  
Feeding Systems

The paper presents results of studies on anti-cavitation properties of propellant-feeding systems of advanced oxygen/hydrogen engines when they operate on boiling hydrogen. It provides a description of an algorithm for conducting cyclic cavitation tests on booster turbopump assemblies. It also provides a schematic of a test setup developed at CADB. Test runs of the setup were preceded by prolonged analytical effort which included profiling of new versions of axidiagonal impellers, CFD flow simulations to evaluate the efficiency of the proposed profilings, constructing a non-stationary model and writing the software that can simulate the operation of the setup. The software made it possible to evaluate the effect of regime parameters on the test setup operation. The final part of the effort was running tests on the setup using hydrogen. The tests provided cavitation characteristics of three booster turbopump assemblies at various flow rates and temperatures of liquid hydrogen. The test results made it possible to update the math model taking into account special profiling features of the axidiagonal impellers. Key words: LOX-LH2 rocket engine, booster turbopump assembly, cavitation, vapor content.

Automatic Unloading Liquid Rocket Engine Fuel Feed System Booster Pump Radial Thrust Bearings from Axial Force

2021 ◽  
pp. 54-61
Author(s):  
S.F. Timushev ◽  
A.A. Frolov
Keyword(s):  
Axial Force ◽  
High Speed ◽  
Rocket Engine ◽  
Liquid Rocket Engine ◽  
Engine Fuel ◽  
Fuel Feed ◽  
Thrust Bearings ◽  
Booster Pump ◽  
Liquid Rocket ◽  
Radial Thrust

Increasing the suction capacity, efficiency and energy parameters of high-speed pumps is an important task in the development of power systems in the aerospace industry, as well as in their application in energy and oil production. With improved cavitation properties, the pumps can operate at a higher shaft speed, and at its given value - with lower cavitation reserves, i.e. at a reduced inlet pressure. When the shaft speed increases, the pump weight and overall dimensions decrease. To increase the anti-cavitation qualities of pumps in the power system, auxiliary (booster) pumping units are used, creating the pressure necessary for the cavitation-free operation of high-pressure and high-speed main pumps of the engine fuel supply system. In accordance with its purpose, the booster pump must provide the required supply pressure of the specified flow rate at the lowest possible liquid pressure at the inlet. At the same time, the efficiency of the booster pump unit should be maximum, and the overall dimensions and weight should be minimal. The last two characteristics predetermine the maximum possible number of revolutions of the pump shaft. Ensuring the operability of the ball-bearing supports of the fuel supply units is one of the most important and complex tasks in the development of modern and promising liquid rocket engines (LRE), especially reusable ones. This task has always been one of the priorities in the fine-tuning the fuel feed units of such engines. The article proposes a method for calculating and controlling the unloading liquid rocket engine booster pump radial thrust bearings from axial force. The method can be applied in the entire range of liquid rocket engine calculations. The further development of this work will be mathematical modeling of the operation of the booster pump automatic axial force unloading.

Measurements of Rotordynamic Coefficients of Hybrid Bearings With: (A) A Plugged Orifice, and (B) A Worn Land Surface

2000 ◽  
Author(s):  
Franck Laurant ◽  
Dara 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 24600 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.

Effect of Centrifugal Force On Gas Flow in a Supersonic Turbine

2021 ◽  
Author(s):  
Takeshi Kanda ◽  
Akio Nakai ◽  
Tatsuya Inagaki ◽  
Tatsuro Asano ◽  
Yasutaka Ohkuma ◽  
...  
Keyword(s):  
Shock Wave ◽  
Mach Number ◽  
Centrifugal Force ◽  
High Speed ◽  
Gas Flow ◽  
Rocket Engine ◽  
Leading Edge ◽  
Rotor Blades ◽  
Turning Angle ◽  
Liquid Rocket

Abstract The flow condition between the rotor blades of a liquid rocket engine supersonic turbine was studied experimentally and numerically. The entrance Mach number was 1.94, and the turning angle of the blades was 120°. A shock wave was created at the leading edge of the blade, and the Mach number in the passage between the blades decreased to around unity. A similar deceleration has been reported in several past studies. It was found that centrifugal force created the shock wave at the leading edge, reducing both the Mach number and total pressure. This phenomenon is characteristic of high-speed blades with large turning angles. The Mach number in the passage was restricted when the mass flow rate was specified under the specified passage configuration. A convergent-divergent configuration of the passage between the blades suppresses the performance degradation of supersonic turbines.

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