Research On Flow Distribution In Parallel Channels For High-temperature Hydrocarbon Fuel With Pyrolysis Considered

The research of this article aims at the flow maldistribution in scramjetregenerative cooling systems. Experimental and modeling methods are both taken touncover the law of flowrate distribution in parallel cooling channels of scramjet,which involves rapid and tremendous temperature change. Effects of chemicalpyrolysis is specificly studied. At last a cascade throttle structure is designed torestrain the flow maldistribution in parallel channels.Firstly, this article simplify the cooling system of scramjet into several paralleltubes. Based on this physical structure an one-dimensional distributed parameteranalytical model is established to study the law of flow distribution. The crack ofhydrocarbon fuel is described by overall reaction mechanism. During which,components and mass fraction of products follow the assumption of PPD. Besides,phenomenon of flow maldistribution and measure to restrain it are introducedthrough the simulation of the classical operating conditions.Secondly, a parallel tube experimental system is built on the experimentalplatform of high-temperature hydrocarbon fuel. Experimental study of is carried outwithin the temperature capacity of the system. It’s found that variety of densitystrongly affects the flow distribution and a category pattern based on differenttemperature conditions of the fuel in parallel channels is raised. Other than theclassical hydrocarbon fuel-kerosene (RP-3), a new type hydrocarbon fuel is alsostudied. Results are indicated to be universal in hydrocarbon fuel to some extent.Then, the effect of chemical pyrolysis is studied by analytical model. Somespecial phenomenon due to pyrolysis are found and explained in different level ofthermal deviation. The pattern of category of temperature conditions iscomplemented and the most dangerous pattern is pointed out. Experiments usingRP-3and a new type of hydrocarbon fuel, which are carried out at the maximumtemperature capacity of the system, verify that maldistribution is more severe thananalytic results.