In the present research, we experimentally verified partial-fill effect in a multi-cycle pulse detonation rocket engine (PDRE).Intermittent thrust of PDRE was measured by using spring-damper mechanism that smoothes this intermittent time direction.The mass flow rates were assessed gas cylinder pressure or difference measurement.The maximum specific impulse 305±9 seconds at an ethylene and oxygen propellant fill fraction 0.130±0.004.When greater than 0.130, increased as partial decreased.When...

A comparison of the numerical predictions several groups modeling reacting flow inside a gaseous methane/gaseous oxygen single-element rocket combustion chamber is conducted. The focus placed on turbulence quantities and their influence computed mean fields. However, subject this paper not pure study model variation, but it aims at showing its effect within framework different overall setups. These comprise differences in models as well codes used. Several Reynolds-averaged Navier–Stokes...

A detailed chemical kinetic mechanism for hypergolic ignition of in a gas mixture has been constructed. In this mechanism, the is mainly caused by sequential reactions H atom abstraction from . Although first step endothermic, consecutive , 2, and 1 are exothermic, especially heat release reaction large because production. Temperature rise accelerates endothermic initiation This thermal feedback responsible at low temperatures. Because no experimental theoretical information available on...

The pulse firing mode of bipropellant thrusters is crucial for the precise attitude control spacecraft. This research explains how to simultaneously measure chamber pressure and observe combustion dynamics in consecutive monomethylhydrazine mixture nitrogen tetroxide with approximately 3% nitric oxide thruster. study investigated transient behaviors ignition cutoff There was a delay measuring two reasons: time needed propellant fill manifold, response pressure-sensing system. manifold...

The features of one-dimensional unsteady detonations are studied numerically using a hydrogen-air detailed chemical reaction model. A series simulations carried out while degree overdrive, initial pressure, temperature, and equivalence ratio varied. oscillation modes mechanisms the discussed with reference to shock pressure histories x-t diagrams density distributions. As overdrive is reduced stoichiometric mixture at P0=0.421atm T0=293K, steady state appears, along high-frequency mode...

A film cooling technique using a liquid subjected to hot gas flow in turbulent condition is theoretically investigated. We successfully incorporate the two essential factors for evaporating film, droplet entrainment and three-dimensional architecture, allowing physically consistent straightforward formulation. The validity of present model conveyed by reproducing combustion test results conducted types flight-model bipropellant thrusters, which length or dryout point shortens approximately...

For LOX/LH2 shear coaxial injectors, it is well-known that high-frequency combustion instabilities may occur when the injection temperature of hydrogen decreases below a certain value, but mechanism initiation instability with injector still not clear. In present study, firing tests were conducted five types single elements by using LOX and LH2 as propellants to further investigate during temperature-ramping changes injection. Results showed unstable was initiated decreased less than...

Regenerative cooling is still one of key technologies to develop high performance liquid rocket engines. To achieve efficiency and reliability, understanding accurate prediction flowfield heat transfer characteristics in regeneratively cooled thrust chambers are prerequisite. In the current study, a fully conjugated combustion simulation for full-scale was proposed demonstrated LE-5B chamber. strategy, injection processes hot-gas side, conduction chamber wall, channel flows taken into...

The oscillation mechanism and reignition process of one-dimensional unsteady detonations are numerically studied using a one-step chemical reaction model governed by Arrhenius kinetics. A series simulations, without perturbations from the outflow boundary to detonation front, carried out while degree overdrive, f, is varied between 1.10 1.74 (f=D2/DCJ2; where D velocity). Shock pressure histories x–t diagrams utilized in order attain precise understanding detonations. At higher degrees...

Understanding and predicting the flowfield heat transfer characteristics in cooling channels are prerequisite to improve design performance of regeneratively cooled rocket thrust chambers. In order realize them, a CFD code, able predict such characteristics, is developed based on pressure-based solver cubic-type equation state take into account real gas effect. As preliminary study, simulations transcritical parahydrogen flows uniformely heated circular tube performed validate code against...

In recent years, methane has attracted attention as a propellant for liquid rocket engines because of its various advantages compared to typical propellants such hydrogen. When is used coolant regenerative cooling system, near-critical thermodynamic and transport properties experience large variations critical pressure higher than that propellants; this significantly influences the flowfield heat transfer characteristics. Therefore, adequate understanding characteristics in channels...

We conduct a high-speed visualization of coolant liquid film dynamics inside 10N-class bipropellant thruster using monomethylhydrazine and mixture nitrogen tetroxide with approximately 3% nitric oxide as propellants at equivalent conditions the flight model. The direct quartz glass chamber demonstrates transient flow from ignition to cutoff for first time. scenario life is found follows: fuel jet impinges on wall being film; friction force rapidly decelerates one-tenth injection velocity;...

The performance of liquid rocket expander bleed cycle engine system strongly depends on a regenerative cooling to provide the required heat in Main Combustion Chamber (MCC). prediction MCC wall transfer characteristics and temperature distributions is very important for designing new engine. Developing tool combined analysis among combustion gas region, chamber structure, channel our ultimate goal. As part development, we carried out numerical simulations flow fields an injector, order...

The physical phenomena in the liquid rocket combustion chamber are very complicated such as turbulence, reaction, and real-gas effect. prediction of heat flux on wall is a challenging problem due to these complex physics This work aimed particularly at validation for turbulent boundary layer three situations; heated flat plate, with pressure gradient, recirculation zone expansion tube. Each situation corresponds straight part chamber, nozzle, exit injectors. For Reynolds-Averaged...