A study of high speed flows in an aircraft transition duct

Abstract

Coefficient in hot wire caUbration equation Area of element of domain partition Constants in moment integral calculations Taylor's series coefficients for five-hole probe pressure coefficient functions Coefficient in hot wire calibration equation, constant in law of the wall equation Constants in moment integral calculations Ethylene concentration expressed as a mole fraction Maximum ethylene concentration for a given cross stream concentration distribution Ethylene concentration coefficient Mean concentration Fluctuating concentration Sonic velocity Sonic velocity at isentropic stagnation conditions Constants in moment integral calculations Diameter Turbulent diffusion coefficient tensor components with respect to Cartesian coordinates Molecular diffusion coefficient Scaler turbulent diffusion coefficient Hot wire anemometer bridge voltage Mean hot wire anemometer bridge voltage Fluctuating hot wire anemometer bridge voltage Five-hole probe pressure coefficient functions Boundary layer shape factor xiii k Constant in law of the wall equation L Length Fluctuating turbulent mixing length with respect to Cartesian coordinates Representative turbulent mixing length M Mach number ^centerline Mach number of the axial velocity component at tlie centerline at i/D =-0.5 M* Velocity coefficient n Exponent in hot wire calibration equation, molar quantity of matter "ethylene Molar quantity of ethylene Uy, U: Exponent parameters in transition duct equation p Static pressure j\yQ\\ Surface static pressure ai xfD =-0.5 ^settling chamber Pressure measured in settling chamber PI,... ,7)5 Pressures measured with five-hole probe p* Static pressure coefficient pn Total pressure Po,centerline Centerline total pressure at i/D =-0.5 PQ Total pressure coefficient R Swirl generator radius, straight pipe radius, transition duct inlet radius, autocorrelation function Ty, Tj Radius parameters in transition duct equation Re Reynolds number Critical Reynolds number ReD Transition duct Reynolds number based on transition duct inlet diameter S Trace gas source strength Tu Turbulence intensity xiv U, y, W Ui Velocity components with respect to Cartesian coordinates U, V, W Ui Mean velocity components with respect to Cartesian coordinates u',v',xi)' It'-Fluctuating velocity components with respect to Cartesian coordinates xvi

Heat transfer computations of internal duct flows with combined hydraulic and thermal developing length

“…This Mach number profile was also compared with its experimental results. 1 The comparison showed good agreement between the results from the computation and the experiment. Some computational results of the surface pressure, the skin friction factor, and the heat transfer coefficient were described in the following sections.…”

“…The downstream static pressure boundary condition (p/p ∞ = 0.985) was chosen from the experimental results. 1 The purpose of the computation was to predict the surface heat transfer coefficients. Therefore, the surface temperature of the experiment 6 was used as the surface temperature boundary condition at r = R. The experiment imposed a step increase in the wall surface temperature along the X-direction and the surface temperature was uniform along the θ-direction.…”

“…This could be due to the generation of the vortices at the transition duct corner locations. 1 NASA TM-107450…”

“…The objective of this study was to investigate the capability of the Navier-Stokes code to predict the heat transfer coefficients at the wall surface of an experimental transition duct. 1 The transition duct, Fig. 1, changed its circular cross section at the upstream locations to rectangular cross section at the downstream locations.…”

Reynolds-Stress Model Prediction of 3-D Duct Flows

“…2) is an H-grid of x-wise varying square cross-section with uni- Wellborn et al (1994) [71,72]. A turbulent intensity T u CL i = 0.63% was applied at the centerline; Wellborn et al [71, p. 29] report this value from measurements of Reichert [56] on the same facility. In the absence of experimental data, a turbulent lengthscale T CL i = 50 mm was assumed at the centerline, with reference to the duct radius (R CSG A = 0.1021 m).…”