A Novel Thermal Method for Rapid Coke Measurement in Liquid Rocket Engines

ABSTRACT: The surfaces of rocket engine thrust chambers, throats and nozzles are exposed to combustion products at temperatures ranging from 4000 to 6000 degrees F and therefore engines must utilize a cooling mechanism to prevent metal failure. Unfortunately, regenerative cooling leaves coke deposits in the fuel channels which can lead to wall failure. Moreover, the recent interest in reusing launch vehicles increases the likelihood that over the course of several missions dangerous levels of coke would eventually be reached. Therefore, there is a need to develop a method to characterize the layer thickness so that engine lifetimes and service intervals can be predicted. Because of the complexity of the channel geometry and the very low levels of coke present, this is a difficult and challenging problem. However Reaction Systems LLC has identified a thermal approach that will rapidly and accurately map the coke deposited in all flow channels. The method is safe and easy to use and has no potential to cause damage to the engine or leave parts behind in the channels. BENEFIT: Successful completion of this project will result in enabling technology that will allow liquid fueled rocket engines to be reused safely. In addition, we believe this technology could find application in the chemical industry to map coke deposition on heterogeneous catalysts used in chemical process industry. Coking is a common catalyst deactivation mechanism in cases where the reaction is carried out under reducing conditions, for example fuel reforming, hydrogenation and dehydrogenation, and fuel production reactions such as Fischer Tropsch (FT). Catalyst regeneration is an expensive task and developing techniques to identify specific reactor sections where the catalyst has lost activity due to coking would permit regeneration of only those portions of the reactor where it is required.