High Thrust to Weight Bipropellant Reentry Vehicle Thrust Vector Control Thru Micro-Miniaturization
Abstract
With the advent of nanosat and picosat-size satellites, the design of miniature, efficient, high thrust-to-weight (T/W) ratio thrust vector control (TVC) thrusters with liquid bipropellants has been evolving. The extremely high T/W ratios achievable with micro miniaturization of liquid bipropellant engines are a result of the "cube-square-law". As the engine is scaled down linearly, the propellant flow, and thus the power, decreases with chamber cross-sectional area or the square of the linear size, while the weight decreases with the volume of the engine or the cube of the linear size As a result, the power-to-weight ratio increases linearly as the engine size is reduced. Only recently, by going to micron-scale microelectromechanical system (MEMS) silicon wafer fabrication technology, has the increase in TAV ratio at reduced bipropellant engine scales been realized over existing T/W ratios for TVC thrusters MEMS and possibly nanotechnology fabrication techniques are the enabling technologies for achieving these higher propulsive system T/W ratios. A fundamental problem with achieving high specific impulse or thrust performance at these reduced engine scales is the combustion residence time. By increasing combustion chamber pressure and adjusting oxidizer to fuel mixture ratio to fuel rich at these reduced engine scales, efficient bipropellant combustion is shown to he analytically and experimentally achievable at engine characteristic lengths one to two orders of magnitude smaller then characteristic lengths of typical spacecraft or satellite TVC thrusters. The advantages of using reduced scale TVC thrusters in improving reentry vehicle (RV) targeting accuracy and mission impulse. requirements will be discussed with RV and nano RV reaction control systems
Document Details
- Document Type
- Technical Report
- Publication Date
- May 08, 2003
- Accession Number
- ADA414922
Entities
People
- William Figueiredo
Organizations
- Air Force Research Laboratory