Topic
Rocket
About: Rocket is a research topic. Over the lifetime, 14018 publications have been published within this topic receiving 95852 citations. The topic is also known as: rockets.
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TL;DR: In this paper, a gaseous film with ambient tempered hydrogen was injected in the axial direction at the face plate of a high-pressure subscale combustion chamber operated with the cryogenic propellant combination LOX=GH2 was used.
Abstract: By the application of film cooling in addition to regenerative cooling, a considerable reduction in thermal and structural loads of rocket combustion-chamber walls can be reached. This paper discusses important influence parameters on film cooling in terms of efficiency of the injected film and wall temperature reduction. For the experimental investigations a high-pressure subscale combustion chamber operated with the cryogenic propellant combination LOX=GH2 was used. A gaseous film with ambient tempered hydrogen was injected in the axial direction at the face plate. Typical film-cooling parameters such as film blowing rate, velocity ratio between film injection velocity and hot-gas velocity, circumferential slot positioning, and film injection slot height were investigated systematically at the European Research and Technology Test Facility P8.
33 citations
16 May 2005
TL;DR: Pratt & Whitney (P&W) is developing the technology for airbreathing hypersonic components and engines as discussed by the authors, and two successful flight tests in 2004, one approaching Mach 7 and the other near Mach 10, of the P&W-designed, NASP-derived, Hyper-X hydrogen -fueled scramjet have provided flight data for code validation.
Abstract: Pratt & Whitney (P&W) is developing the technology for airbreathing hypersonic components and engines. A supersonic combustion ramjet (scramjet) database was developed during the National Aero Space Plane (NASP) program using hydrogen fueled propulsion systems for space access vehicles. Two successful flight tests in 2004, one approaching Mach 7 and the other near Mach 10, of the P&W-designed, NASP-derived, Hyper-X hydrogen -fueled scramjet have provided flight data for code validation. The Air Force Research Laboratory (AFRL) Hypersonic Technology (HyTech) Office has put programs in place to continue the NASP vision, incrementally, by developing the technologies necessary to demonstrate the operability, performance, and structural durability of a liquid hydrocarbon fueled scramjet system that operates from Mach 4 to 8. Flight tests of a flight-weight, fuel-cooled hydrocarbon scramjet under the Scramjet Engine Demonstrator-WaveRider (SED-WR) program are planned for 2008–2010 under AFRL and Defense Advanced Research Program Agency (DARPA) sponsorship. The application of scramjet engine technology as part of combined cycle propulsion systems is also being pursued. The combination of scramjet power and solid rocket booster acceleration is applicable to hypersonic cruise missiles. Scramjets that use gas turbines for low-speed acceleration and scramjets using rocket power are being studied for application to hypersonic cruise vehicles and reusable launch systems. P&W’s recent activities and future plans for hypersonic propulsion will be described.
33 citations
13 Jul 1998
TL;DR: This article developed a vortex regression law that predicts the regression rate as a function of scaling, injector pattern, and injector diameter, and solid fuel type, which can be tailored by modifying the injector geometry.
Abstract: ORBITEC has been developing a new type of hybrid rocket under NASA MSFC Phase I and II SBIR's where the gaseous oxidizer is injected tangent to the inner fuel grain surface either through or at the bottom of the fuel grain wall. The resulting combustion chamber flow field is a bi-directional co-axial vortex where the spinning flow migrates up the outer wall to the head end of the engine, flows inwards towards the center of the engine, and out the engine nozzle. The motivations for developing this unique hybrid are that it regresses over 8 times faster than a conventional head end injected hybrid at a comparable oxidizer mass flux. Additionally, the flow field increases the effective combustion stay time for a given size chamber volume and nozzle throat area. It is expected that these two characteristics will allow increased hybrid performance, the use of a simple single port grain geometry, and increased grain case volumetric loading efficiency. It has also been discovered that the regression rate of this vortex hybrid can be tailored by modifying the injector geometry. Gaseous oxidizer would be used in flight versions of the engine where the full flow staged combustion cycle or expander cycle can gasify and deliver the oxygen. The experimental results of the Phase I effort are presented here. A total of 32 firings were conducted to investigate the effects of scaling, injector pattern, injector diameter, and solid fuel type. The vortex flow field was characterized through smoke testing, oil streak testing, and filtered video data of the firings. The fuel regression rate was found to be strongly dependant upon the injector geometry, oxidizer mass flux, and the corresponding strength of the vortex. Statistical analysis was used to develop a vortex regression law that predicts the regression rate as a function of these parameters. The Phase IISBIR is currently being performed where a 500 Ibf engine will be designed and tested.
33 citations
Patent•
07 Jul 1938
TL;DR: In this paper, a combustion chamber particularly designed for use in rockets, planes and other aircraft in which continuous combustion of liquid constituents takes place at very high temperature is described. But the authors do not discuss the effective provision for cooling the walls of the combustion chamber without...
Abstract: This invention relates to a combustion chamber particularly designed for use in rockets, rocket planes and other aircraft in which continuous combustion of liquid constituents takes place at very high temperature. Effective provision for cooling the walls of sucIrcombustion chambers without...
33 citations
15 Jun 1988
TL;DR: In this paper, the problem of on-board trajectory optimization for an airbreathing, single-stage-to-orbit vehicle is examined, and a simple model representative of the aerospace plane concept, including a dual-mode propulsion system composed of SCRAMJET and rocket engines is presented.
Abstract: The problem of on-board trajectory optimization for an airbreathing, single-stage-to-orbit vehicle is examined. A simple model representative of the aerospace plane concept, including a dual-mode propulsion system composed of SCRAMJET and rocket engines, is presented. Consideration is restricted to hypersonic flight within the atmosphere. An energy state approximation is employed in a four-state model for flight of a point mass in a vertical plane. Trajectory constraints, including those of dynamic pressure and aerodynamic heating, are initially ignored. Singular perturbation methods are applied in solving the optimal control problem of minimum fuel climb. The resulting reduced solution for the energy state dynamics provides an optimal altitude profil1e dependent on energy level and control for rocket thrust. A boundary-layer analysis produces an approximate lift control solution in feedback form and accounts for altitude and flight path angle dynamics. The reduced solution optimal climb path is presented for the unconstrained case and the case for which a maximum dynamic pressure constraint is enforced.
33 citations