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.

Numerical Study on Rotor-Stator Interaction of a Supersonic Reaction Turbine for a Liquid Rocket Engine

2010 ◽  
Author(s):  
Kaname Kawatsu ◽  
Naoki Tani ◽  
Nobuhiro Yamanishi
Keyword(s):  
Shock Wave ◽  
Mach Number ◽  
Flow Field ◽  
Nozzle Exit ◽  
Rocket Engine ◽  
Leading Edge ◽  
Liquid Rocket Engine ◽  
Turbine Efficiency ◽  
Rotor Stator Interaction ◽  
Liquid Rocket

For an open cycle liquid rocket engine, such as the expander bleed cycle, the mass flow rate of turbine driving gas should be small, especially to improve rocket engine performance. However, work output must be high as possible. As a result, pressure ratio of the turbine becomes high, and Mach number at both nozzle exit and rotor inlet becomes supersonic. As a result, strong shock wave interaction can be generated between nozzle exit and rotor inlet, and this interaction affects the turbine aerodynamic performance. However, this rotor-stator interaction of supersonic turbine has not yet been clarified. Therefore, as the first step, it is important to clarify the structure of the flow field and to evaluate the accuracy of CFD method as practical engineering tool for liquid rocket engine design. In the present study, quasi 3-D RANS simulations were applied to the NACA supersonic turbine and the numerical results were compared with the experimental ones to evaluate numerical methodology. Turbulence models and rotor/stator interface modeling method were compared, and their impacts to the turbine aerodynamic performance estimation were evaluated. In addition to these points, the flow field between nozzle and rotor region and the turbine efficiency were investigated. The present results clarify some features of rotor-stator interaction. The shock wave, which is generated near the nozzle exit caused by encounter of nozzle exit flow, reflects at the neighbor nozzle wall and affects the rotor region. At the same time, the shock wave from the rotor leading edge impinges the nozzle cascade, and these shocks interact with each other. The present results showed that Mach number at nozzle outlet becomes different due to each turbulence and rotor/stator interface models. This difference of Mach number influences the shape of detached shock wave at the leading edge of rotor blade, and changes the entire rotor region flow field such as static pressure profile of rotor region. Thus, turbine efficiency may be influenced by these different features of flow field.

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.

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.

Optimization of Aerodynamic Parameters of Cropped Delta Wing with Fence at Sonic Mach Number

2019 ◽  
Vol 16 (2) ◽  
pp. 403-409
Author(s):  
M. P. Arun ◽  
M. Satheesh ◽  
Edwin Raja J. Dhas
Keyword(s):  
Shock Wave ◽  
Boundary Condition ◽  
Mach Number ◽  
Sound Speed ◽  
Delta Wing ◽  
Leading Edge ◽  
Supersonic Speed ◽  
Sweep Angle ◽  
Ansys Fluent ◽  
Aerodynamic Parameters

Manufacturing and maintaining different aircraft fleet leads to various purposes, which consumes more money as well as man power. Solution to this, nations that are leading in the field of aeronautics are performing much research and development works on new aircraft designs that could do the operations those were done by varied aircrafts. The foremost benefit of this delta wing is, along the huge rearward sweep angle, the wing’s leading edge would not contact the boundary of shock wave. Further, the boundary is produced at the fuselage nose due to the speed of aircraft approaches and also goes beyond the transonic to supersonic speed. Further, rearward sweep angle greatly worse the airspeed: wings under normal condition to leading edge, so permits the aircraft to fly at great transonic, subsonic, or supersonic speed, whereas the over wing speed is kept to minimal range than that of the sound speed. The cropped delta wing with fence has analysed in three cases: Fences at 3/4th distance from the centre, with fences at half distance from the centre and with fences at the centre. Further, the delta wing that cropped is exported to ANSYS FLUENT V14.0 software and analysed by making the boundary condition settings like sonic Mach number of flow over wing along with the angle of attack.

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.

scholarly journals Controlled-Endwall-Flow Blading for Multistage Axial Compressor Rotor

1997 ◽  
Author(s):  
M. Inoue ◽  
M. Kuroumaru ◽  
M. Furukawa ◽  
Y. Kinoue ◽  
T. Tanino ◽  
...  
Keyword(s):  
High Speed ◽  
High Efficiency ◽  
Axial Compressor ◽  
Internal Flow ◽  
Leading Edge ◽  
Rotor Blades ◽  
Advanced Technology ◽  
Low Flow ◽  
Surge Margin ◽  
Highly Loaded

This research aims to develop an advanced technology of highly loaded axial compressor stages with high efficiency and sufficient surge margin. To improve endwall boundary layer flows which lead to energy loss and instability at an operation of low flow rate, the Controlled-Endwall-Flow (CEF) rotor blades were designed and tested in the low speed rotating cascade facility of Kyushu University. The CEF rotor blades have three distinctive features: the leading-edge sweep near hub and casing wall, the leading-edge bend near the casing, and the same exit metal angle of blade evaluated by a conventional design method. Mechanical strength of the blade was verified by a numerical simulation at a high speed condition. The baseline rotor blades were designed under the same design condition and tested to compare with the CEF rotor. The results showed that the maximum stage efficiency of the CEF rotor was higher by 0.7 percent and the increase in surge margin was more than 20 percent in comparison with the baseline rotor. The results of both internal flow survey and 3D Navier-Stokes analysis showed that improvement of the overall stage performance resulted from activation of the endwall boundary layers, and suggested that further improvement might be expected by combination of end-bend stator blades and a highly loaded axial compressor stage could be developed by use of the CEF rotor.

Simulation of blunt-fin-induced shock-wave and turbulent boundary-layer interaction

1985 ◽  
Vol 154 ◽  
pp. 163-185 ◽  
Author(s):  
Ching-Mao Hung ◽  
Pieter G. Buning
Keyword(s):  
Boundary Layer ◽  
Shock Wave ◽  
Flat Plate ◽  
High Speed ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Leading Edge ◽  
Horseshoe Vortex ◽  
Layer Interaction ◽  
Boundary Layer Interaction

The Reynolds-averaged Navier–Stokes equations are solved numerically for supersonic flow over a blunt fin mounted on a flat plate. The fin shock causes the boundary layer to separate, which results in a complicated, three-dimensional shock-wave and boundary-layer interaction. The computed results are in good agreement with the mean static pressure measured on the fin and the flat plate. The main features, such as peak pressure on the fin leading edge and a double peak on the plate, are predicted well. The role of the horseshoe vortex is discussed. This vortex leads to the development of high-speed flow and, hence, low-pressure regions on the fin and the plate. Different thicknesses of the incoming boundary layer have been studied. Varying the thicknesses by an order of magnitude shows that the size of the horseshoe vortex and, therefore, the spatial extent of the interaction are dominated by inviscid flow and only weakly dependent on the Reynolds number. Coloured graphics are used to show details of the interaction flow field.

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.

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