Engineering topics

Champion, R. H., Jr.

Publications and source records attributed to Champion, R. H., Jr..

6 records

NASA NTRS1998

Pressurization, Pneumatic, and Vent Subsystems of the X-34 Main Propulsion System

In pressurization systems, regulators and orifices are use to control the flow of the pressurant. For the X-34 Main Propulsion System, three pressurization subsystem design configuration options were considered. In the first option, regulators were used while in the other options, orifices were considered. In each design option, the vent/relief system must be capable of relieving the pressurant flow without allowing the tank pressure to rise above proof, therefore, impacts on the propellant tank vent system were investigated and a trade study of the pressurization system was conducted. The analysis indicated that design option using regulators poses least risk. Then, a detailed transient thermal/fluid analysis of the recommended pressurization system was performed. Helium usage, thermodynamic conditions, and overpressurization of each propellant tank were evaluated. The pneumatic and purge subsystem is used for pneumatic valve actuation, Inter-Propellant Seal purges, Engine Spin Start, and engine purges at the required interface pressures, A transient analysis of the pneumatic and purge subsystem provided helium usage and flow rates to Inter-Propellant Seal and engine interfaces. Fill analysis of the helium bottles of pressurization and pneumatic subsystems during ground operation was performed. The required fill time and the stored

Hedayat, A.↗

NASA NTRS1998

Propellant Feed Subsystem for the X-34 Main Propulsion System

The Orbital Sciences Corporation X-34 vehicle demonstrates technologies and operations key to future reusable launch vehicles. The general flight performance goal of this unmanned rocket plane is Mach 8 flight at an altitude of 250,000 feet. The Main Propulsion System supplies liquid propellants to the main engine, which provides the primary thrust for attaining mission goals. Major NMS design and operational goals are aircraft-like ground operations, quick turnaround between missions, and low initial/operational costs. This paper reviews major design and analysis aspects of the X-34 propellant feed subsystem of the X-34 Main Propulsion System. Topics include system requirements, system design, the integration of flight and feed system performance, propellant acquisition at engine start, and propellant tank terminal drain.

McDonald, J. P.↗

NASA NTRS1998

Propellant Management and Conditioning within the X-34 Main Propulsion System

The X-34 hypersonic flight vehicle is currently under development by Orbital Sciences Corporation (Orbital). The Main Propulsion ystem as been designed around the liquid propellant Fastrac rocket engine currently under development at NASA Marshall Space Flight Center. This paper presents analyses of the MPS subsystems used to manage the liquid propellants. These subsystems include the propellant tanks, the tank vent/relief subsystem, and the dump/fill/drain subsystem. Analyses include LOX tank chill and fill time estimates, LOX boil-off estimates, propellant conditioning simulations, and transient propellant dump simulations.

Brown, T. M.↗

NASA NTRS1998

Transient Analysis of X-34 Pressurization System

Two transient operational modes of the X-34 pressurization system were analyzed using the ROCket Engine Transition Simulation (ROCETS) program. The first operational mode considers the normal operation. For the engine burn period, the required helium mass and pressure of each propellant tank were calculated. In the second case, the possibility of failure of the pressurization system solenoid valves, its consequence on the over-pressurization, and simultaneous operation of pressurization and vent/relief systems were evaluated.

Hedayat, A.↗

NASA NTRS1998

Subsystem Analysis/Optimization for the X-34 Main Propulsion System

The Orbital Sciences Corporation X-34 vehicle demonstrates technologies and operations key to future reusable launch vehicles. The general flight performance goal of this unmanned rocket plane is Mach 8 flight at an altitude of 250,000 feet. The Main Propulsion System (MPS) supplies liquid propellants to the main engine, which provides the primary thrust for attaining mission goals. Major MPS design and operational goals are aircraft-like ground operations, quick turnaround between missions, and low initial/operational costs. Analyses related to optimal MPS subsystem design are reviewed in this paper. A pressurization system trade weighs maintenance/reliability concerns against those for safety in a comparison of designs using pressure regulators versus orifices to control pressurant flow. A propellant dump/feed system analysis weighs the issues of maximum allowable vehicle landing weight, trajectory, and MPS complexity to arrive at a final configuration for propellant dump/feed systems.

McDonald, J. P.↗

NASA NTRS1998

X-34 Main Propulsion System-Selected Subsystem Analyses

The X-34 hypersonic flight vehicle is currently under development by Orbital Sciences Corporation (Orbital). The Main Propulsion System (MPS) has been designed around the liquid propellant Fastrac rocket engine currently under development at NASA Marshall Space Flight Center. This paper presents selected analyses of MPS subsystems and components. Topics include the integration of component and system level modeling of the LOX dump subsystem and a simple terminal bubble velocity analysis conducted to guide propellant feed line design.

Brown, T. M.↗