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Controllable Propulsion System for a Generic Ejection Seat.7 Numerical Methods Overview The CFD-ACE flow solver is the primary analysis tool for the present study.The code solves the Navier-Stokes equations in a general curvilinear coordinate system using a finite-volume pressure based method.The code employs structured grids and support multiple–domain and grid-blockage techniques.The code also employs a variety of spatial-differencing schemes including first-order upwind,second-order upwind,central,and Osher-Chakravarthy.For this study,the second-order upwind method was employed.CFD-ACE also supports a variety of turbulence models.For this study,a standard ke turbulence model with wall functions was employed.This turbulence model has been shown to produced good comparisons with wind tunnel test data for ejection seats[1~5].
The CFD-ACE code supports frozen,finite-rate,and equilibrium chemistry options with thermodynamic and transport properties supplied by a JANNAF type thermodynamic database.The solid propellants commonly used in escape systems are reduced smoke(non-aluminized),hazard class 1.3 propellant.Since aluminum is not a combustion product,the need for modeling solid particulate is eliminated[6].Therefore,the standard chemistry models of CFD-ACE are sufficient for modeling the solid rocket motor nozzle and plume flow fields.The combustion modeling employed in this study will be discussed in detail in the computational results section.
Code Validation CFD-ACE has been validated and applied to a wide variety of problems involving fluid flow,heat transfer,turbulence,mixing of chemical species,finite-rate chemistry,two-phase flows, moving/rotating bodies, and other problems.In particular,CFD-ACE has been extensively validated for escape system flow fields[1-5].
All of the computational cases were conducted using the second-order upwind spatial differencing scheme and the k-εturbulence model.The gas properties were specified using the chemistry database discussed previously.The boundaries of the computational domain were specified in the following manner.A total pressure and total temperature boundary condition was applied at the nozzle inlet with PT=2500psi(1.724E7 Pa)and TT=4981 F(3023 K).The chemical composition at the nozzle inlet was specified according to Table 1.An extrapolation boundary condition was applied at the nozzle exit where the flow field was supersonic.The pintle and nozzle walls were modeled with a viscous,adiabatic wall condition,and a symmetry condition was applied along the centerline of the nozzle.The thrust and mass flow for each case were computed by numerically integrating the following the equations at the nozzle exit: where r is the radial coordinate,R is the nozzle exit radius,and P∞=1atm.
Comparison of Measured and Computed Nozzle Thrust Profiles In Fig. 6,the thrust versus pintle position profiles predicted by the series of CFD solutions is compared to the profiles derived from the Aerojet test data.The equilibrium and frozen chemistry simulations predict almost identical thrust profiles,and both compare well with the test data.Both the CFD and test results produce a nearly linearly thrust profiles as a function of pintle position.At the lower thrust settings,the CFD simulations tend to over predict the nozzle thrust.This phenomenon was also reported in the Aerojet analysis[13]and was attributed to thermal expansion and ablation of the nozzle throat.

Characterization The structure of the raw material was characterized by X-ray diffractometer (performed using Cu Kα radiation (λ = 0.15418 nm), step-scan mode with step size, 0.02° 2θ; counting time, 0.25s per step, X’Pert PRO MPD, PANalytical, Netherlands).
Singh, Chemistry of D-Block Elements, Discovery Publishing House, New Delhi, pp. 15–320
Lange's Handbook of Chemistry, 15th Edn.
Industrial & Engineering Chemistry d Water Leaching."
Industrial & Engineering Chemistry Research 52(45): 15756-15762.

X-ray analysis was used to make phase and structure analysis.
The Rietveld method was applied for structure refinement.
They are characterized by the presence of vacancies in crystal structure and by relatively big lattice parameters.
Its structure was described as NiAs type structure, space group I m 2 .
Structure refinement.

The chemical composition and phase structure of adsorbents were characterized by X–Ray fluorescence spectroscopy (XRF) and X–ray diffraction (XRD), respectively.
This results indicated that intra–pore structured the formation and addition of chemical and physical adherent capabilities of most surfaces of the pores with condensed units of copper nitrate.
It is noteworthy that such structure inside the pores provides stability and enhances reproducibility of H2S adsorption on to the copper–impregnated diatomite and leonardite and the recovery of the modified diatomite and leonardite [8].
The advantage of diatomite is that it has more silica content, small particle size with the porous structure.
Thanks for the Department of Chemistry, Faculty of Science, Maejo University, Chiang Mai, Thailand, the Materials Science Research Center (MSRC), Faculty of Science, Chiang Mai University, Chiang Mai, Thailand, and the Department of Chemistry, Faculty of Science and Technology, Uttaradit Rajabhat University, Uttaradit, Thailand.

Experimental The chemistry compositions of raw materials used in the experiments was shown in the table 1.
Table4 The mineral compositions (%) Schemes Hematite Magnetite Calcium ferrite Dicalcium silicate Perovskite Glass phase Gangue Scheme1 15 40 35 5-7 - 1-3 1-2 Scheme2 15 40-45 30-35 2-3 1-3 3 1-2 Scheme3 15-20 35-40 30-35 3 2-3 3 2-3 Scheme4 15 35-40 30-35 3-5 3 3 3-5 Scheme5 20 30 30 3-5 5-10 3 3-5 As Fig.4(a) shown, most of magnetite and calcium ferrite formed mixed corrosion structure, and the different levels of perovskite exist in the different structure.
The perovskite grains exist within mixed corrosion of structure and between the crystals of calcium ferrite.
For a small number of Hematite, the internal is filled by dicalcium silicate and glass phase and a few scattered granular hematites located in the middle of interwoven structure.
Some magnetite and calcium ferrite formed corrosion structure and small number of calcium ferrite formed interwoven structure itself.

The binary polymer AA/SAS was synthesized by acrylic acid (AA) and sodium allylsulfonate (SAS), named as AS and its structure was characterized.
Barium and strontium inhibitors: CT, provided by Yangtze University Oilfield Chemistry Laboratory; TF, from Shandong Taihe Water Treatment Co., LTD.
And its structure was characterized and confirmed by infrared spectrum.
Preparation and Application of Phosphinate Scale Inhibitor SIB [J].Oilfield Chemistry, 2005, 22(1):32-34.
Improvements in Volumomentric Analysis for Strontium and Barium Ionic Concentrations in Oilfield Formation Water [J].Oilfield Chemistry, 1988, 5(4):301-306.

Nano-porous structure is attractive since it exhibits excellent structural stability would enhance the volumetric energy density compared with the irregularly shaped nanoparticles.
Therefore, the Mn2O3 microspheres with the porous structure would be an ideal cathode material precursor.
Interestingly, the precursor powers are porous spherical structure under TEM, and there are many nanopores among the particles.
Materials Chemistry and Physics.
Chemistry a European Journal. (2012), Vol. 19, Issue 34 [8] Sonalika Vaidya, Pallavi Thaplyal, Ashok Kumar Ganguli.

XRD revealed the detail information on the crystallographic structure and phase formation of the materials.
The crystallite size, D of the structures calculated from XRD pattern was shown in Table 1.0.
It is observed that the morphology obtained from ZnO was hexagonal nanorod like structure.
Fig 3 (b),(c), (d) presents the structure agglomerate and no grain boundaries.
Bioinorganic chemistry and applications 2014 (2014)

China 2 Chemistry Department , Harbin Institute of Technology, Harbin, 150001, P.
The influences of the precursor, additive, reaction pH and temperature on phase and textural structures of the products were investigated.
The goal is to provide new and efficient routes for obtaining crystalline and well structured mesoporous titania materials for potential use. 2.
Taking into account the effect of additive on crystal structure of titania, we added (NH4)2SO4 in TiCl4 aqueous solution.
Wang, Journal of Physics and Chemistry of Solids. 69 (2008) 1147-1151 [3] E.L.

XRD pattern confirmed that the Fe3O4 microspheres belong to cubic structure.
X1 X3 X2 X4 X6 X5 Fig. 1 SEM images of the Fe3O4 microspheres Fig. 2 XRD patterns of the typical Fe3O4 microspheres Structure of the samples.
This indicates that the as-synthesized samples are pure Fe3O4 phase with cubic structure.
Fig. 5 Hysteresis loops of the Fe3O4 microspheres Conclusion The magnetic Fe3O4 microspheres with cubic structure were synthesized by a solvothermal method.
Ni: Progress in Chemistry Vol. 21 (2009), p. 880 [4] P.