Impact of Liquid Propellant Properties on Small Rocket Thruster Dimensions
Abstract
A study has been made of how the physical properties of the liquid propellants hydrazine and hydrogen peroxide influence energy conversion device dimensions across multiple operating configurations. The energy conversion device was a staged rocket thruster comprised of a first stage where propellant is decomposed to create a high temperature, low velocity environment and a second stage downstream where propellant is injected and exothermically decomposed. The operating configurations varied chamber pressure, propellant flow rate ratio of first stage to second stage, and ratio of propellant feed pressure to chamber pressure within the thruster. Chamber pressures of 125, 250, and 500 psi; flow rate ratios of 1:3, 1:4, and 1:5; and feed to chamber pressure ratios of 1.25:1 and 1.75:1 were considered. The study utilizes relationships that were empirically derived to estimate droplet sizes as a function of the propellant physical properties and various related operating conditions. As the chamber pressure and feed to chamber pressure ratio increased, the chamber dimensions decreased. As the flow rate ratio decreased, the chamber length increased. Relative to the primary reference, Ryan, instant study theoretical values achieved were consistently 30-50% low. Contributing to the disagreement, was use of injector orifice diameters below those of the reference which would drive increased injection velocity values and drive the results lower.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 2012
- Accession Number
- ADA590109
Entities
People
- Anthony Zuttarelli
- Tim Fox
Organizations
- Air Force Research Laboratory