The Combustion Laboratory

[ Home ]                    [ Research Areas ]                    [ Human Resources ]                    [ Selected Publications ]

Mixing of Cryogenic Fluids in Rocket Injectors
Investigators: Vivek Gautam, Ahmed Abdelhafez, Jakub Gmurczyk


Overview

The objective of this research is to work with NASA engineers and researchers to examine the mixing behavior of various cryogenic, non-cryogenic propellants and their simulants from a realistic rocket engine injector. Our goal is to provide detailed information on shear layer and other modes of mixing and its subsequent effect on ignition, stability and performance in a single element of the rocket injector under atmospheric pressure and simulated in-space conditions. The detailed database will be used for model validation and model development. The approach used is both experimental and theoretical.




Sample Images from High Speed Cameras


High speed image of unconfined LN2/GN2 flow with no recess
High speed image of unconfined 
LN2/GN2 flow with 0.2 inch recess 		Shlieren movie of LN2/GN2 flow

High speed image of unconfined LN2/CO2 flow (MR = 12)
High speed image of unconfined 
LN2/He flow (MR = 40)

Distribution of centerline temperature for the IR 
thermal images




Sample Images from IR Thermal 


IR thermal image of unconfined LN2/GN2 flow with 
no recess
IR thermal image of unconfined LN2/GN2 flow with 
0.2 inch recess

Temperature distribution (°C) for unconfined
LN2/CO2 flow with no recess (MR = 12)
Temperature distribution (°C) for unconfined LN2/He 
flow with no recess (MR = 40)





Sample Schlieren Images


LN2/CO2 (MR = 5.6)
LN2/He (MR = 5.6)
LN2/He (Swirl Number = 5 , MR = 5.6)





Sample Results on Ignition Behavior of H2/O2 and CH4/O2 Mixtures





PIV Results


Flowfield distribution with He (inner pipe) / O2
(outer annulus) case
Flowfield distribution with He (inner pipe) / CO2
(outer annulus) case

Axial velocity distribution at a distance of Y = 0.16 D 
from the injector exit
Shear strain distribution at a distance of Y = 0.16 D
from the injector exit








 

Last Edited: May 13, 2006