Characterization of supercritical reactive flow for hypersonic real-time application

Abstract

In the framework of the hypersonic propulsion, with cooled engine by endothermic hydrocarbon fuel, it is necessary to provide adapted measurement methods for the cooling regulation as for the control of the engine thrust. The sensors should be robust because of the extreme in-flight conditions, of vehicle acceleration and vibration, of the fluid temperature (1500 K) and pressure (3.5 MPa) and of the multi-component supercritical mixture. Their response time should be lower than one second. Therefore, a large range of real time and on line measurement methods has been tested and some of these methods among the most promising are presented in this paper. The aim is not to necessarily develop a new technology but to evaluate the feasibility and the adaptability of existing ones for our purpose, even if those are not especially dedicated for it. Numerical evaluation is firstly conducted then some of the techniques are experimentally tested. Two of them, the sonic throat and the Fourier Transform Infra Red spectroscopy (FTIR), appear to be particularly promising and allow uncertainties of few percents. The first one allows evaluating the mass flow rate of a supercritical reactive mixture. The second one characterizes the chemical composition before injection in the combustion chamber, for mole fraction greater than 5 %.

Synthetic and jet fuels pyrolysis for cooling and combustion applications

“…Further validations of fluid temperature have been presented in previous work [20]. Finally, the code has been validated experimentally on sub-and supercritical fluid [15] under stationary conditions then under transient ones [21]. The molar fractions are found to be estimated with a discrepancy lower than 2 %, which is also the one of the transient experimental method when compared with GC/MS data [22].…”

Real-time method for the identification and quantification of hydrocarbon pyrolysis products: Part II. Application to transient pyrolysis and validation by numerical simulation

“…The COMPARER project (COntrol and Measure of PArameters in a REacting stReam) has been settled in 2003 to enable studying the regenerative cooling technique. To control such a technology, the combustion of the hydrocarbon pyrolysis products should be assessed and this requires estimating the main components and their respective concentrations [10]. For this purpose, a specific Infra Red method has been developed and validated under steady-state conditions [11].…”

Measurements for fuel reforming for scramjet thermal management and combustion optimization: 2009 status of the COMPARER project

“…Many different measurements have been investigated, that are in principle usable for qualifying the decomposed hydrocarbon fuel. Some of them are detailed in 9 . The present paper gives some information on the IR methods that where particularly investigated in the second phase of the COMPARER program.…”