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.
Physico-Chemistry of Planetary Atmospheric Entry Plasmas
This contribution deals with the description of the physico-chemistry in the reactive flow produced near the surface of a body entering a planetary atmosphere in hypersonic regime. A shock layer is formed in which a boundary layer is developed where energy is released to the body surface. N2 is chosen as a test-case of Earth atmospheric reentry to illustrate the main characteristics of the flow. The vibrational and electronic specific Collisional-Radiative model CoRaM-N2 is described and implemented in a one-dimensional Euler flow solver. The well-known FIRE II flight experiment conditions are used to illustrate the behaviour of the different ground and excited states of atomic and molecular species. The results show that the three successive phases occur: vibrational excitation, dissociation and ionisation. Radiation plays a minor role. According to the upstream thermodynamic conditions, the boundary layer edge can be in local thermodynamic equilibrium or not. The different strategies using thermal protection systems are discussed to reduce the damaging of the entering body.
Experimental study on bond behavior between high-strength grout and deformed steel bars
Abstract Engineers use high-strength grout to connect precast concrete members for its low shrinkage and good fluidity. This paper designed 87 central pull-out specimens using the control variable method to investigate the influence of factors on the rebar-grout bond property such as compressive strength, steel grade, bar diameter, transverse stirrups, and bond length. The test result showed that improving grout compressive strength (85.8 MPa–122.7 MPa) cannot improve the bond strength, which was different from the previous conclusions of concrete pull-out tests. Simplified formulas were presented for calculating the characteristic values of bond strength, residual strength, peak slip, and relative slip of load-holding platform based on parameter analysis. Then, a constitutive model was proposed to predict the full-range bond stress-slip curve of high-strength grout and steel bar specimens from bearing to failure. Finally, FEA models were established to evaluate the applicability and accuracy of the constitutive model.