Injector and Combustion Chamber Design for a Nitrous Oxide and Ethanol Rocket Engine

Mapping Intimacies ◽

10.31224/osf.io/8vngq ◽

2021 ◽

Author(s):

Giovani Ceotto ◽

Guilherme Castrignano Tavares

Keyword(s):

Nitrous Oxide ◽

Combustion Chamber ◽

Rocket Engine ◽

Fuel Mixture ◽

Static Test ◽

One Dimensional ◽

Swirl Injector ◽

Acoustic Cavities ◽

Pressure Swirl ◽

Ongoing Project

The basic design of a rocket engine injector and combustion chamber for saturated nitrous oxide and liquid ethanol is presented. At first, an oxidant-fuel mixture is selected based on a thermochemical analysis that explores several existing options and other combinations that have not yet been studied. As a result, nitrous oxide is chosen as an oxidant and ethanol as fuel. Then a simplified methodology is proposed for the design of a pressure-swirl injector responsible for ethanol. Computational fluid dynamics is used to verify the validity of the above-mentioned analysis, using Volume of Fluid (VOF). For the nitrous oxide injector, the flash-boiling phenomenon is investigated, verifying its importance for the ongoing project. The effect is treated analytically using the Dyer model to account for non-equilibrium thermodynamics. Simplified zero-dimensional and one-dimensional combustion models are explored as tools to design the rocket combustion chamber. Furthermore, combustion instability due to acoustic phenomena is studied, with the first spinning tangential mode being computed for the herein developed motor and an ensemble of acoustic cavities being developed to suppress the aforementioned mode. Finally, a diagram of the static test bench which will be used to validate the injectors and the designed engine is also presented.

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Injector and Combustion Chamber Design for a Nitrous Oxide and Ethanol Rocket Engine

10.31224/osf.io/bjm68 ◽

2021 ◽

Author(s):

Guilherme Castrignano Tavares ◽

Giovani Ceotto

Keyword(s):

Nitrous Oxide ◽

Combustion Chamber ◽

Rocket Engine ◽

Fuel Mixture ◽

Static Test ◽

One Dimensional ◽

Swirl Injector ◽

Acoustic Cavities ◽

Pressure Swirl ◽

Ongoing Project

This report presents the basic design of a rocket engine injector and combustion chamber for saturated nitrous oxide and liquid ethanol, as well as details of the construction and operation of the engine in which the injectors will be used. At first, an oxidant-fuel mixture is selected based on a thermochemical analysis that explores several existing options and other combinations that have not yet been studied. As a result, nitrous oxide is chosen as an oxidant and ethanol as fuel. Then a simplified methodology is proposed for the design of a pressure-swirl injector responsible for ethanol. Computational fluid dynamics is used to verify the validity of the above-mentioned analysis, using Volume of Fluid (VOF). For the nitrous oxide injector, the flash-boiling phenomenon is investigated, verifying its importance for the ongoing project. The effect is treated analytically using the Dyer model to account for non-equilibrium thermodynamics. Simplified zero-dimensional and one-dimensional combustion models are explored as tools to design the rocket combustion chamber. Furthermore, combustion instability due to acoustic phenomena is studied, with the first spinning tangential mode being computed for the herein developed motor and an ensemble of acoustic cavities being developed to suppress the aforementioned mode. Finally, a preliminary diagram of the static test bench which will be used to validate the injectors and the designed engine is also presented.

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Review on pressure swirl injector in liquid rocket engine

Acta Astronautica ◽

10.1016/j.actaastro.2017.12.038 ◽

2018 ◽

Vol 145 ◽

pp. 174-198 ◽

Cited By ~ 20

Author(s):

Zhongtao Kang ◽

Zhen-guo Wang ◽

Qinglian Li ◽

Peng Cheng

Keyword(s):

Rocket Engine ◽

Liquid Rocket Engine ◽

Swirl Injector ◽

Liquid Rocket ◽

Pressure Swirl

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Effect of Chemical Hythane Composition on Pressure in Combustion Chamber of Engine

Alternative Energy and Ecology (ISJAEE) ◽

10.15518/isjaee.2019.10-12.036-042 ◽

2019 ◽

pp. 36-42

Author(s):

A. P. Shaikin ◽

I. R. Galiev

Keyword(s):

Natural Gas ◽

Combustion Chamber ◽

Power Plants ◽

Engine Speed ◽

Combustion Engine ◽

Fuel Mixture ◽

Maximum Pressure ◽

Chamber Volume ◽

Excess Air ◽

Scientific Papers

The article analyzes the influence of chemical composition of hythane (a mixture of natural gas with hydrogen) on pressure in an engine combustion chamber. A review of the literature has showed the relevance of using hythane in transport energy industry, and also revealed a number of scientific papers devoted to studying the effect of hythane on environmental and traction-dynamic characteristics of the engine. We have studied a single-cylinder spark-ignited internal combustion engine. In the experiments, the varying factors are: engine speed (600 and 900 min-1), excess air ratio and hydrogen concentration in natural gas which are 29, 47 and 58% (volume).The article shows that at idling engine speed maximum pressure in combustion chamber depends on excess air ratio and proportion hydrogen in the air-fuel mixture – the poorer air-fuel mixture and greater addition of hydrogen is, the more intense pressure increases. The positive effect of hydrogen on pressure is explained by the fact that addition of hydrogen contributes to increase in heat of combustion fuel and rate propagation of the flame. As a result, during combustion, more heat is released, and the fuel itself burns in a smaller volume. Thus, the addition of hydrogen can ensure stable combustion of a lean air-fuel mixture without loss of engine power. Moreover, the article shows that, despite the change in engine speed, addition of hydrogen, excess air ratio, type of fuel (natural gas and gasoline), there is a power-law dependence of the maximum pressure in engine cylinder on combustion chamber volume. Processing and analysis of the results of the foreign and domestic researchers have showed that patterns we discovered are applicable to engines of different designs, operating at different speeds and using different hydrocarbon fuels. The results research presented allow us to reduce the time and material costs when creating new power plants using hythane and meeting modern requirements for power, economy and toxicity.

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Spray Cone Angles by a Pressure Swirl Injector for Atomization of Gelled Ethanol

10.26678/abcm.cobem2017.cob17-0549 ◽

2017 ◽

Author(s):

Gustavo Alexandre Achilles Fischer ◽

JOSE CARLOS ANDRADE ◽

FERNANDO COSTA

Keyword(s):

Spray Cone ◽

Swirl Injector ◽

Pressure Swirl

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Preliminary Studies on Non-Reactive Flow Vortex Cooling

Recent Patents on Mechanical Engineering ◽

10.2174/2212797612666190510115403 ◽

2019 ◽

Vol 12 (3) ◽

pp. 262-271

Author(s):

T.N. Rajesh ◽

T.J.S. Jothi ◽

T. Jayachandran

Keyword(s):

Combustion Chamber ◽

Inner Core ◽

Rocket Engine ◽

Injection Pressure ◽

Chamber Pressure ◽

Reactive Flow ◽

Stoichiometric Ratio ◽

Gaseous Oxygen ◽

Mixture Ratio ◽

Vortex Combustion

Background: The impulse for the propulsion of a rocket engine is obtained from the combustion of propellant mixture inside the combustion chamber and as the plume exhausts through a convergent- divergent nozzle. At stoichiometric ratio, the temperature inside the combustion chamber can be as high as 3500K. Thus, effective cooling of the thrust chamber becomes an essential criterion while designing a rocket engine. Objective: A new cooling method of thrust chambers was introduced by Chiaverni, which is termed as Vortex Combustion Cold-Wall Chamber (VCCW). The patent works on cyclone separators and confined vortex flow mechanism for providing high propellant mixing with improved degree of turbulence inside the combustion chamber, providing the required notion for studies on VCCW. The flow inside a VCCW has a complex structure characterised by axial pressure losses, swirl velocities, centrifugal force, flow reversal and strong turbulence. In order to study the flow phenomenon, both the experimental and numerical investigations are carried out. Methods: In this study, non-reactive flow analysis was conducted with real propellants like gaseous oxygen and hydrogen. The test was conducted to analyse the influence of mixture ratio and injection pressure of the propellants on the chamber pressure in a vortex combustion chamber. A vortex combustor was designed in which the oxidiser injected tangentially at the aft end near the nozzle spiraled up to the top plate and formed an inner core inside the chamber. The fuel was injected radially from injectors provided near the top plate and the propellants were mixed in the inner core. This resulted in enhanced mixing and increased residence time for the fuel. More information on the flow behaviour has been obtained by numerical analysis in Fluent. The test also investigated the sensitivity of the tangential injection pressure on the chamber pressure development. Results: All the test cases showed an increase in chamber pressure with the mixture ratio and injection pressure of the propellants. The maximum chamber pressure was found to be 3.8 bar at PC1 and 2.7 bar at PC2 when oxidiser to fuel ratio was 6.87. There was a reduction in chamber pressure of 1.1 bar and 0.7 bar at PC1 and PC2, respectively, in both the cases when hydrogen was injected. A small variation in the pressure of the propellant injected tangentially made a pronounced effect on the chamber pressure and hence vortex combustion chamber was found to be very sensitive to the tangential injection pressure. Conclusion: VCCW mechanism has been to be found to be very effective for keeping the chamber surface within the permissible limit and also reducing the payload of the space vehicle.

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