Combined Measurements and Computations of High Enthalpy and Plasma Flows for Determination of TPM Surface Catalycity
TITLE: Measurement Techniques for High Enthalpy and Plasma Flows [Techniques de mesure pour les ecoulements de plasma et les ecoulements a haute enthalpie] To order the complete compilation report, use: ADA390586 The component part is provided here to allow users access to individually authored sections f proceedings, annals, symposia, ect. However, the component should be considered within he context of the overall compilation report and not as a stand-alone technical report. The paper presents the method for the TPM catalycity 3,5m/s V prediction on the basis of high enthalpy plasmatron heat 102rn/c transfer tests, performed in subsonic regimes, and 1400 appropriate CFD modeling of the whole plasma flow field in the plasma wind tunnel (1), viscous reacting gas ,5 flows around a test model (2), a nonequilibrium 12=1,0m0s boundary layer near the stagnation point of a test model 1200 (3) and analysis of the the heat transfer for test conditions l • 0m/s at the small Reynolds and Mach numbers (4). In general, the methodology was developed during the study of the 1000 catalytic efficiencies of the Buran TPM-the black 0 1 2 3 X, m ceramic tile and the CC material with antioxidation coating-in dissociated nitrogen and air reacting flows. Fig. 1. Surface temperature distribution along the windward This experimental-theoretical methodology has been center line of the Bor vehicle [ref 8]. Dots-the flight test modified recently for the determination of TPM data: I-CC material with antioxidation coating; 2-ceramic catalycity in subsonic carbon dioxide and pure oxygen tile, 3-ceramic tile covered with black platinum. Curves-flows from high enthalpy tests performed by using the computations at different catalytic recombination rates Kw. 100-kW inductive IPG-4 plasmatron. The interaction between combined ground test measurements and CFD modeling is considered as genesis for catalytic effects Tw, K duplication, plasma flow field rebuilding and the extraction of the quantitative catalycity parameters from the measured high enthalpy flow parameters, surface temperature and stagnation point heat fluxes.
PHENOMENOLOGICAL THEORY FOR HETEROGENEOUS RECOMBINATION OF PARTIALLY DISSOCIATED AIR ON HIGH-TEMPERATURE SURFACES
Simulation of heterogeneous catalytic recombination of partially dissociated air without chemical equilibrium in flow on the high temperature surfaces of hypersonic vechicle thermoprotection system started in the 1950-th [1],[2]. As energy of oxigen or nitrogen molecule less than one of two oxigen or nitrogen atoms respectively, the energy releasing during the atomic recombination transmitted to the surrounding gas (homogeneous recombination) or to the surface (heterogeneous recombination). In 1960–1970 calculated models of heterogeneous reactions in dissociated air were reduced to the formal consideration of two extreme boundary condition cases: unreal noncatalytic surface model and assumption of ideal catalytic one, that essentially encrease radiation equilibrium surface temperature [3]. Since 1980 systematic experimental [4],[5] and theoretical [6]–[10] investigations carried out to predict heterogeneous recombination probability (HRP) γ o and γ n on the thermal protection reusable insolations (“tiles”). The approximation of HRP experimental data γ i (i = O, N) in the Arrhenius form [4] for the materials was found to be unusable in the wide range of surface temperature; for the agreement with the experimental data an activation energy must change with the temperature. The recombination reaction rate dependence on pressure was also discovered. Moreover, the comparison Space Shuttle experiments data with the calculated heat fluxes obtained using only the temperature depending catalytic constant \( \left( {{{k}_{{\omega i}}} = \gamma \sqrt {{kT/2\pi {{m}_{i}}}} } \right) \) does not give satisfactory agreement everywhere along the vehicle surface and in all points of glide reentry trajectory. This indicates that hetero-geneous recombination of partially dissociated air on real thermoprotection materials is multi-step process including elementary steps. On the base of ideal adsorbed layer Langmuir concept generalized and developed by M.P.Temkin [11], the structural dependence of the effective coefficient of catalytic activity via pressure, temperature and mixture composition first was obtained in references [7]–[10].
Achievements and contradictions of the Peruvian agrarian reform
Different paths of transition to capitalist agriculture, as well as different types of agrarian reform, can be distinguished. The Peruvian agrarian reform is analysed within this context and evaluated in terms of its contribution to rural development. The Peruvian case underlines the importance of understanding the rationality of the pre‐existent agrarian system for a successful restructuring of the agrarian economy and society. The contradictions which arose between the State's model and the peasants’ model of agrarian reform, as well as those between different types of peasants, are discussed. Peru's experience is also a reminder that a land reform is not a sufficient condition for rural development unless accompanied by proper price, marketing, credit and investment policies.