Additives to Increase Fuel Heat Sink Capacity

Recently, NASA has increased its emphasis on reducing the cost of reaching low Earth orbit. The goal is to reduce the cost from the current $10,000 per pound of payload to $100 per pound. Studies indicate that a key technology requirement is a single stage to orbit (SSTO) using rocket based combined cycle (RBCC) engine. In the third stage of a RBCC launch, an air breathing vehicle will travel at speeds from Mach 5 to Mach 10 prior to exiting the atmosphere. Under these conditions, the vehicle requires cooling in excess of that available through sensible heating of the fuel. Although this heating can be supplied by endothermic cracking of the fuel prior to combustion, the temperatures required to achieve necessary rates are very high. High temperatures reduce the allowable stress in the heat exchanger, increasing its weight and reducing its efficiency. In this Phase I SBIR, TDA Research, Inc. (TDA) proposes to test chemical initiators that greatly accelerate the rate of thermal cracking reactions, allowing them to proceed at lower temperatures. We will then carry out a systems analysis which will model the behavior of the fuel passing through the test section, allowing us to identify the most effective operating conditions.