Supersonic Flow Separation with Application to Rocket Engine Nozzles

The past decade has seen a qualitative advancement of our understanding of physical phenomena involved in flow separation in supersonic nozzles; in particular, the problem of side loads due to asymmetrical pressure loads, which constitutes a major restraint in the design of nozzles for satellite launchers. The development in this field is to a large extent motivated by the demand for high-performance nozzles in rocket engineering. The present paper begins with an introduction to the physical background of shock-boundary-layer interactions in basic 2D configurations, and then proceeds to internal axisymmetric nozzle flow. Special attention is given to past and recent efforts in modeling and prediction, turning physical insight into applied engineering tools. Finally, an overview is given on different technical solutions to the problem if separation and side loads, discussed in the context of rocket technology.

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A study into the feasibility of using the oxygen-hydrocarbon engine 11D58M as a basis for development of a high-performance multifunctional gas-generatorless rocket engine with oxygen cooling

Space engineering and technology ◽

10.33950/spacetech-2308-7625-2019-2-67-80 ◽

2019 ◽

pp. 67-80

Author(s):

Boris A. Sokolov ◽

Nikolay N. Tupitsyn

Keyword(s):

Film Cooling ◽

High Performance ◽

Rocket Engine ◽

Hydrocarbon Fuel ◽

Gas Generator ◽

Automatic Equipment ◽

The Us ◽

Upper Stage ◽

Pump Assembly ◽

Turbo Pump

The paper presents results of engineering studies and research and development efforts at RSC Energia to analyze and prove the feasibility of using the mass-produced oxygen-hydrocarbon engine 11D58M with 8.5 ton-force thrust as a basis for development of a high-performance multifunctional rocket engine with oxygen cooling and 5 ton-force thrust, which is optimal for upper stages (US), embodying a system that does not include a gas generator. The multi-functionality of the engine implies including in it additional units supporting some functions that are important for US, such as feeding propellant from US tanks to the engine after flying in zero gravity, autonomous control of the engine automatic equipment to support its firing, shutdown, adjustments during burn and emergency protection in case of off-nominal operation, as well as generating torques for controlling the US attitude and stabilizing it during coasting, etc. Replacing conventional engine chamber cooling that uses high-boiling hydrocarbon fuel with the innovative oxygen cooling makes it possible to get rid of the internal film cooling circuits and eliminate their attendant losses of fuel, while the use of the oxygen gasified in the cooling circuit of the chamber to drive the turbo pump assembly permits to design an engine that does not have a gas generator. Key words: Multifunctional rocket engine, oxygen cooling, gas-generatorless design, upper stage.

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Insight into the structure-capacity relationship in biomass derived carbon for high-performance sodium-ion batteries

Journal of Energy Chemistry ◽

10.1016/j.jechem.2021.04.009 ◽

2021 ◽

Vol 62 ◽

pp. 497-504

Author(s):

Jianguo Sun ◽

Yao Sun ◽

Jin An Sam Oh ◽

Qilin Gu ◽

Weidong Zheng ◽

...

Keyword(s):

High Performance ◽

Sodium Ion ◽

Sodium Ion Batteries ◽

Insight Into

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Design of a Novel Miniaturized Frequency Selective Surface Based on 2.5-Dimensional Jerusalem Cross for 5G Applications

Wireless Communications and Mobile Computing ◽

10.1155/2018/3485208 ◽

2018 ◽

Vol 2018 ◽

pp. 1-6 ◽

Cited By ~ 3

Author(s):

Peng Zhao ◽

Yihang Zhang ◽

Rongrong Sun ◽

Wen-Sheng Zhao ◽

Yue Hu ◽

...

Keyword(s):

Resonant Frequency ◽

Equivalent Circuit ◽

Equivalent Circuit Model ◽

Frequency Selective Surface ◽

Size Reduction ◽

Two Dimensional ◽

Physical Insight ◽

Frequency Selective ◽

Significant Size ◽

Insight Into

A compact frequency selective surface (FSS) for 5G applications has been designed based on 2.5-dimensional Jerusalem cross. The proposed element consists of two main parts: the successive segments of the metal traces placed alternately on the two surfaces of the substrate and the vertical vias connecting traces. Compared with previous published two-dimensional miniaturized elements, the transmission curves indicate a significant size reduction (1/26 wavelengths at the resonant frequency) and exhibit good angular and polarization stabilities. Furthermore, a general equivalent circuit model is established to provide direct physical insight into the operating principle of this FSS. A prototype of the proposed FSS has been fabricated and measured, and the results validate this design.

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Insight into the Metabolic Profiles of Pb(II) Removing Microorganisms

Molecules ◽

10.3390/molecules26134008 ◽

2021 ◽

Vol 26 (13) ◽

pp. 4008

Author(s):

Carla Cilliers ◽

Evans M. N. Chirwa ◽

Hendrik G. Brink

Keyword(s):

Liquid Chromatography ◽

High Performance ◽

Microbial Consortium ◽

Luria Bertani ◽

Nutrient Concentrations ◽

Batch Experiments ◽

Metabolic Study ◽

Luria Bertani Broth ◽

Tandem Mass Spectroscopy ◽

Insight Into

The objective of the study was to gather insight into the metabolism of lead-removing microorganisms, coupled with Pb(II) removal, biomass viability and nitrate concentrations for Pb(II) bioremoval using an industrially obtained microbial consortium. The consortium used for study has proven to be highly effective at removing aqueous Pb(II) from solution. Anaerobic batch experiments were conducted with Luria-Bertani broth as rich growth medium over a period of 33 h, comparing a lower concentration of Pb(II) with a higher concentration at two different nutrient concentrations. Metabolite profiling and quantification were conducted with the aid of both liquid chromatography coupled with tandem mass spectroscopy (UPLC-HDMS) in a “non-targeted” fashion and high-performance liquid chromatography (HPLC) in a “targeted” fashion. Four main compounds were identified, and a metabolic study was conducted on each to establish their possible significance for Pb(II) bioremoval. The study investigates the first metabolic profile to date for Pb(II) bioremoval, which in turn can result in a clarified understanding for development on an industrial and microbial level.

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New Insight into Microstructure Engineering of Ni‐Rich Layered Oxide Cathode for High Performance Lithium Ion Batteries

Advanced Functional Materials ◽

10.1002/adfm.202010095 ◽

2021 ◽

pp. 2010095

Author(s):

Chul‐Ho Jung ◽

Do‐Hoon Kim ◽

Donggun Eum ◽

Kyeong‐Ho Kim ◽

Jonghyun Choi ◽

...

Keyword(s):

Lithium Ion Batteries ◽

High Performance ◽

Lithium Ion ◽

Layered Oxide ◽

Oxide Cathode ◽

Insight Into

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Endwall Blockage in Axial Compressors

Journal of Turbomachinery ◽

10.1115/1.2841344 ◽

1999 ◽

Vol 121 (3) ◽

pp. 499-509 ◽

Cited By ~ 97

Author(s):

S. A. Khalid ◽

A. S. Khalsa ◽

I. A. Waitz ◽

C. S. Tan ◽

E. M. Greitzer ◽

...

Keyword(s):

Tip Clearance ◽

Design Parameters ◽

Tip Clearance Flow ◽

Axial Compressors ◽

Clearance Flow ◽

Flow Features ◽

Physical Insight ◽

Level Loading ◽

Stagger Angle ◽

Insight Into

This paper presents a new methodology for quantifying compressor endwall blockage and an approach, using this quantification, for defining the links between design parameters, flow conditions, and the growth of blockage due to tip clearance flow. Numerical simulations, measurements in a low-speed compressor, and measurements in a wind tunnel designed to simulate a compressor clearance flow are used to assess the approach. The analysis thus developed allows predictions of endwall blockage associated with variations in tip clearance, blade stagger angle, inlet boundary layer thickness, loading level, loading profile, solidity, and clearance jet total pressure. The estimates provided by this simplified method capture the trends in blockage with changes in design parameters to within 10 percent. More importantly, however, the method provides physical insight into, and thus guidance for control of, the flow features and phenomena responsible for compressor endwall blockage generation.

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

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.320.196 ◽

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.

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