1. 1 DIRECT MEASUREMENT OF CONCENTRATION AT MIXING IN THE HOT-SHOT FACILITY Goldfeld М.А., Starov А.V., Timofeev К.Yu. Khristianovich Institute of Theoretical and Applied Mechanics

2. 2 Yang, M.L., Gu, S.J., Liu, G.E., Li, X.Y., "Trajectory with Diffusion Method for Predicting the Fuel Distribution in a Transverse Stream," AIAA Paper 83-0336, 1983. Shaikhutdinov, Z.G. and Klevanskii, V.M., "Penetration and Mixing of Liquid Injected into Supersonic Transverse Gas Stream" Izvestiya Vysshikh Uchebnykh Zavedenii Aviatsionnaya Tekhnika, Vol. 19, No. 1, 1976, pp. 99-108. Way J., Libby, P. Hot-wire probe for measuring velocity and concentration in helium-air jets mixture. AIAA J., 1970, Vol. 8, #3, pp. 976-978. Adler, D.A. A hot wire technique for continues measurement in unsteady concentration fields in binary gaseous mixture. J. Phis. 1972, Vol.5, pp.163-169. Brown, G., Rebollo, M. A small, fast-response probe to measure composition of a binary gas mixture. AIAA J., 1972, V.10, pp.649-652. Ahmed S., So R. M. Concentraion distribution in a model combustor. Experiments in Fluids, 1986, V. 4, #2, pp107-113. Ng, W. F., Kwok, F. T., and Ninneman, T. A. A Concentration Probe for the Study of Mixing in Supersonic Shear Flows, AIAA Paper 89-2459, July 1989. Ng, W. F., Epstein, A. A. High-frequency temperature and pressure probe for unsteady compressible flows. Review Sci. Instrumen., 1983, vol. 54, pp. 1678-1683. Geometry of aspirating concentration probe

3. 3 Combustor model testing with kerosene fuel Injector Section Attached pipeline operating mode Test Parameters: M= 2-3 P 0 = 10-50bars T 0 = 1700-2500K P, bar  ms

4. 4 Combustor model testing with kerosene fuel at M=2 Static pressure distribution along model x  mm P hot / P cold Best variant of fuel injection: AR+NI Comparison of CI and AR Flow visualization Variants of fuel injections

5. 5 AIMS of investigations:  Determination of fuel mixing at supersonic velocities in channel  development of gas sampling system  tests in the hot-shot wind-tunnel with operating mode up to 100ms  determination of kerosene concentration in combustor sections at fuel supplying through aeroramp  determination of helium concentration at same conditions

6. 6 Gas sampling system Container for gas sample preservation with pressure gage Sampling rake for gas probe

7. 7 Scheme of gas sampling system 1 – screw; 2 – nut; 3, 6 – piston; 4 – cylinder; 5 – connector; 7 – fixator; 8 – pirocartridge; 9 – sampling rake; 10 – packing ring.

8. 8 Concept of determination of kerosene quantity Flow visualization Photo of installed sampling rake The chemical analysis of samples mixture was carried out by means of gas chromatograph LHM-80МD. Accuracy of definition of concentration was less than 1%.

9. 9 Concentration distributions P t = 30атм, T t = 2300K Положение Относительная концентрация Положение Относительная концентрация Положение Относительная концентрация 111.294211.055310.932 121.271221.320321.178 130.181230.386330.915 P t = 50атм, T t = 2300K ПоложениеОтносительная концентрация 111.051 121.535 130.403 ПоложениеПараметры пуска Относительная концентрация 12 P t = 50атм, T t = 2300K0.574 P t = 30атм, T t = 2300K0.521 P t = 30атм, T t = 2000K0.471 Таблица 1 Таблица 2 Таблица 3

10. 10 Concentration distributions Kerosene concentration distribution Helium concentration distribution Effect of flow parameters

11. 11 Developed gas sampling system allowed to obtaining the kerosene and helium distributions in combustor sections. Tests were carry out at M=3. It was investigated at conditions of hot-shot wind tunnel. On the initial part of the channel in the region of a cavity the kerosene distribution on channel height is essentially non-uniformly. The difference of concentration reaches fivefold size. And in a cavity there is overrich mixture, and a poor mixture is in an opposite part of a flow. Further on length of the channel the kerosene portion in the bottom part of the channel increases, and above it decreases. Behind a cavity non-uniformity of the fuel concentration is decreased to 3.5 times differences on height. On distance of 217 mm from entrance kerosene is sufficiently uniformly distributed on cross-section of the channel with a difference no more than 25 %. Change of parameters of an air flow has shown that the pressure increase at the channel entrance does not change qualitative distribution of kerosene on height (minimum of concentration in the bottom part of channel). There are only quantitative distinctions, in particular, fuel portion increasing in a flow core. Measurements of concentration of helium have shown that in contrast to fuel with the big molecular weight, the helium portion in a flow core forms about 50 % from total amount of helium in the model channel. The increase of parameters of an air flow at the entrance leads to rather small (~20 %) growth of a helium size in the investigated section of the channel. Conclusions