VAPORIZING AND ENDOTHERMIC FUELS FOR ADVANCED ENGINE APPLICATION. PART II. STUDIES OF THERMAL AND CATALYTIC REACTIONS, THERMAL STABILITIES AND COMBUSTION PROPERTIES OF HYDROCARBON FUELS.
Abstract
Studies leading toward the development of specifications for heat-sink fuels for hypersonic aircraft are reported. Heat sinks of about 2000 Btu/lb of fuel can be achieved at 1350 F by taking advantage of latent, sensible, and endothermic heat sinks. Rate considerations favor catalytic reactions. The dehydrogenation of methylcyclohexane (MCH) to toluene and hydrogen approaches the above heat sink over a platinum on alumina catalyst. Propane dehydrogenation will yield about 1500 Btu/lb, but the reaction is neither as clean nor as rapid. The thermal stabilities of molecular types generally increase in the order monocyclic aromatic, monocyclic naphthene, bicyclic naphthene, n-paraffin. Exclusion of oxygen increases the critical thermal stability temperature by about 200 F. The introduction of alkyl groups into either the cyclohexane or benzene rings increases thermal stability. A 20-gal/hr adiabatic heat exchanger-reactor system has been constructed and shakedown tests with water have been completed following the execution of a number of changes suggested by preliminary test work. Excellent heat balances have been achieved and satisfactory correlation of heat-transfer data with the literature has been found. Ignition delay data have been obtained utilizing a single-diaphragm shock tube under conditions useful for consideration in the design of supersonic combustion ramjets. Methylcyclohexane and its reaction products and propane and its reaction products have been studied in the range 1300-2700 F. Ignition delays ranged from 100-4000 microseconds under lean conditions, decreasing with temperature. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 16, 1965
- Accession Number
- AD0473845
Entities
People
- A. C. Nixon
- G. H. Ackerman
- H. T. Henderson
- I. S. Bjorklund
- R. D. Hawthorn