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.

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.

scholarly journals Investigation of the Performances of a Diesel Engine Operating on Blended and Emulsified Biofuels from Rapeseed Oil

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6661
Author(s):  
Vladimir Anatolyevich Markov ◽  
Bowen Sa ◽  
Sergey Nikolaevich Devyanin ◽  
Anatoly Anatolyevich Zherdev ◽  
Pablo Ramon Vallejo Maldonado ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Rapeseed Oil ◽  
Characteristic Curve ◽  
Motor Fuel ◽  
Experimental Tests ◽  
Operating Conditions ◽  
Test Results ◽  
Cfd Simulations ◽  
Brake Thermal Efficiency ◽  
Flow Simulations

The article discusses the possibility of using blended biofuels from rapeseed oil (RO) as fuel for a diesel engine. RO blended diesel fuel (DF) and emulsified multicomponent biofuels have been investigated. Fuel physicochemical properties have been analyzed. Experimental tests of a diesel engine D-245 in the operating conditions of the external characteristic curve and the 13-mode test cycle have been conducted to investigate the effect of these fuels on engine performances. CFD simulations of the nozzle inner flow were performed for DF and ethanol-emulsified RO. The possibility of a significant improvement in brake thermal efficiency of the engine has been noted. The efficiency of using blended biofuels from RO as a motor fuel for diesel engines has been evaluated based on the experimental test results. It was shown that in comparison with the presence of RO in emulsified multicomponent biofuel, the presence of water has a more significant effect on NOx emission reduction. The content of RO and the content of water in the investigated emulsified fuels have a comparable influence on exhaust smoke reduction. Nozzle inner flow simulations show that the emulsification of RO changes its flow behaviors and cavitation regime.

A New Method to Measure Prandtl Number and Thermal Conductivity of Fluids

1957 ◽  
Vol 24 (1) ◽  
pp. 25-28
Author(s):  
E. R. G. Eckert ◽  
T. F. Irvine
Keyword(s):  
Thermal Conductivity ◽  
Boundary Layer ◽  
Prandtl Number ◽  
High Velocity ◽  
Atmospheric Pressure ◽  
New Method ◽  
Test Results ◽  
Test Setup ◽  
Velocity Boundary Layer ◽  
Layer Flow

Abstract A new method is described by which the Prandtl number and indirectly the thermal conductivity of fluids can be measured. The method is based on the fact that a well-established, unique relation exists between the Prandtl number and the recovery factor for laminar high-velocity boundary-layer flow. The test setup is described which has been devised for such measurements, and test results are presented for air at atmospheric pressure and temperatures between 60 and 350 F.

In-flight reconfiguration of lithium-ion cells aimed at extending flight times and range of electrically powered UAVs

2019 ◽  
Vol 7 (3) ◽  
pp. 98-111 ◽  
Author(s):  
Svetoslav Zabunov ◽  
Garo Mardirossian
Keyword(s):  
Design Methodology ◽  
Lithium Ion ◽  
Test Results ◽  
Content Type ◽  
Test Setup ◽  
Lithium Ion Cells ◽  
Battery Design ◽  
Novel Design ◽  
Battery Module

Purpose The purpose of this paper is to disclose a novel reconfiguration battery design suitable for electrically powered UAVs. Design/methodology/approach A design of a reconfigurable battery module is presented. Test setup with prototype battery module is developed and described. Test results of measurements are shown and discussed. Findings The results ascertain the benefits of implementing a reconfigurable battery in small electrically powered UAVs and specifically prove the efficiency of the proposed design. Originality/value The proposed novel design is compared to previous work while advances from the latter and the gained advantages were established.

Transient Lift-Off Test Results for an Experimental Hybrid Bearing in Air, Simulating a Liquid Hydrogen Turbopump Start Transient

2016 ◽  
Author(s):  
Dara W. Childs ◽  
David Klooster ◽  
Henry Borchard ◽  
Dustin Pavelek ◽  
Stephen Phillips
Keyword(s):  
Rocket Engine ◽  
Transient Behavior ◽  
Simulation Software ◽  
Test Results ◽  
Unit Load ◽  
Ramp Rate ◽  
Fluid Medium ◽  
Supply Pressure ◽  
Lift Off ◽  
Point Of Departure

Start-transient testing of a hybrid (combined hydrostatic and hydrodynamic action) bearing supplied with air was completed, providing an indication of its performance while operating in a compressible fluid medium. The test start transients were modeled after Rocket Engine Transient Simulation Software (ROCETS) predictions for start-transient behavior of running speed ω(t) and bearing supply pressure Ps(t). The top test speed was 15 krpm. The ramp rate, supply pressure Ps values at 15 krpm, constant bearing unit load magnitude w0, and load orientation (load-on-recess LOR or load-on-land LOL) were varied. Five different load-case combinations were carried out (separately) for LOR and LOL load configurations with ramp rates varying from 2206 rpm/s to 8824 rpm/s. The target pressures at 15 krpm varied from 5.32 bars to 18.25 bars. The tested bearing dimensions were: L = D = 38.1 mm, and Cr =.0635 mm. Lift-off occurs due to the increase in Ps (ω dependent) and was defined as the point of departure towards the center of the bearing with increasing ω while the rotor remained 0.00254 mm (0.1 mils) above the bearing surface. This method is limited by the inability to accurately measure an established operating bearing clearance. Evaluation of the lift-off Ps versus applied unit load w0 supports the following conclusions: (1) Lift-off Ps is approximately a linear function of w0, (2) Changing the ramp rate while keeping constant the specified Ps at 15 krpm has no significant impact, (3) Lowering the limit Ps at 15 krpm may reduce the lift-off Ps value, and (4) The LOR start-transient cases required a higher lift-off speed and lift-off Ps values than the corresponding LOL start-transient cases.

Performance of the Directly-Irradiated Annular Pressurized Receiver (DIAPR) Operating at 20 Bar and 1,200°C

2000 ◽  
Vol 123 (1) ◽  
pp. 10-17 ◽  
Author(s):  
A. Kribus ◽  
P. Doron ◽  
R. Rubin ◽  
R. Reuven ◽  
E. Taragan ◽  
...  
Keyword(s):  
Radiation Flux ◽  
Test Results ◽  
Gas Temperature ◽  
Flow Rates ◽  
Air Temperatures

The Directly Irradiated Annular Pressurized Receiver (DIAPR) is a volumetric (directly-irradiated) windowed cavity receiver, designed for operation at a pressure of 10–30 bar, exit gas temperature of up to 1,300°C, and aperture radiation flux of up to 10 MW/m2. This paper presents test results obtained under various irradiation conditions and flow rates. Inlet aperture flux was up to 5 MW/m2; exit air temperatures of up to 1,200°C were obtained, while operating at pressures of 17–20 bar. Estimated receiver efficiency in these tests was in the range of 0.7–0.9. The absorber and window temperatures were 200-400°C below the permitted maximum, indicating that higher air exit temperatures are possible.

Advanced cryogenic solid hybrid rocket engine developments - Concept and test results

1998 ◽  
Author(s):  
Christopher St. Clair ◽  
Daniel Gramer ◽  
Eric Rice ◽  
William Knuth
Keyword(s):  
Rocket Engine ◽  
Test Results ◽  
Hybrid Rocket ◽  
Hybrid Rocket Engine

A Novel Air Purifier for Trace SO2 Removal and Simulation of the Purification Effect

2015 ◽  
Vol 1092-1093 ◽  
pp. 805-809
Author(s):  
Dong Lai Xie ◽  
Jin Hui Luo
Keyword(s):  
Indoor Air ◽  
Large Scale ◽  
Gas Flow ◽  
Test Results ◽  
Confined Space ◽  
Ansys Fluent ◽  
Flow Rates ◽  
The World ◽  
Air Purifier ◽  
Scale Usage

With the large-scale usage of coal and gasoline, China has been the most serious SO2-polluted country in the world. SO2 can cause respiratory and cardiovascular disease, which does great harm to human health. Therefore, developing an air purifier to absorb trace SO2 is very necessary. According to the mechanism of SO2 absorption with the alkaline solution, we developed an air purifier with an purification capacity of 80m3 -100m3 per hour. The purification effect with different gas flow rates, absorbing liquids and initial SO2 concentration was tested. Test results indicated that the purifier had a very good absorption of trace SO2 for indoor air. A SO2 purification model in confined space was established and the purification effect of the purifier was simulated with ANSYS FLUENT 14.0.

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