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Showing 1 to 20 of 102 for “"Prandtl"”.
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Prandtl-Meyer expansion of an ionizing monatomic gas
The Prandtl-Meyer flow of a pure, monatomic gas, including the effects of ionization and recombination, has been numerically calculated. Expressions describing the thermodynamic state of the gas mixture were obtained from statistical mechanics, the components making up the mixture being considered …
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Prandtl-Meyer expansion of ionized argon with differing electron and atom temperatures
The sharp corner expansion of ionized argon with differing electron and atom temperatures has been calculated. The thermodynamic equations which apply for a two-temperature gas were derived. An energy balance on the electrons was performed to obtain a functional relationship between Ta, Te, p , and …
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Variable Viscosity Thermal Convection at Infinite Prandtl Number in a Thick Spherical Shell
Variable viscosity thermal convection at infinite Prandtl number in a thick spherical shell is modeled using the finite element method. The discretized tensor Navier-Stokes equations are solved with the multigrid method applied to the spherical elements. Numerically convergent solutions can be …
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Solving The Prandtl Boundary Layer Equation in Fluid Dynamics Via Non-Linear Numerical Optimization
… profile is calculated via conformal mapping. The Prandtl boundary layer equation is modified and solved via Mehrstellen Finite Difference formulas having only in finite difference terms. The differential term is replaced by from continuity equation in 2D space.</p>
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A Multi-Resolution Direct Numerical Simulation of Turbulent Stratified Flows with High Prandtl Numbers
… source modelled by the Beer–Lambert law, for Prandtl numbers (𝑃𝑟) ranging 0.07 to 7, is investigated using direct numerical simulation (DNS). Most prior DNS studies of stratified turbulent open-channel flow have been limited to 𝑃𝑟 ≤ 1 due to computational constraints. To overcome the increased …
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Estudo analítico da convecção natural junto a uma placa inclinada para números de Prandtl baixos
… The perturbation equations were solved Prandtl numbers 0.733 and 0.03 and inclination angles and 60. Velocity and temperature profiles are compared to numerically for of the experimental results existing in the literature. Nusselt number versus Grashof number curves are plotted. Limiting …
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Convection and segregation phenomena in low Prandtl number melt growth systems : a quantitative experimental and theoretical approach
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Materials Science and Engineering, 1977
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A spectral method determination of the first critical Rayleigh number for a low-Prandtl number crystal melt in a cylindrical container
… convection is investigated for a low-Prandtl number liquid metal in a cylindrical container. All surfaces are considered to be solid and no-slip. Two cases are considered for the thermal boundary conditions at the side wall: conducting and insulated surfaces. A Chebyshev Galerkin …
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Zonal flow driven by convection and convection driven by internal heating
… steady states with zonal flow are found for Prandtl numbers up to 0.3. Stable and unstable steady states with horizontal periods up to six times the layer height are computed for a Prandtl number of 0.1 and Rayleigh numbers, Ra, up to 2*10⁵. Concurrently stable states with and without zonal …
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Buckling of cantilever thin plate with free end subjected to uniform shear
… shear. The same problem waa originally solved by Prandtl in 1899, based on the equilibrium condition of a deep beam. The author baa used the energy method based on the thin plate theory to attack the problem. After the displacement is assumed, the potential energy can be formulated. From the …
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Thermocapillary Convection During Laser Surface Heating (Surface Tension)
… temperature scale. These formulas depend on the Prandtl number implicitly. Two asymptotic limits, small and large Prandtl numbers, are analyzed. The results provide explicit Prandtl number dependences of all the scalings in the respective ranges. Algebraic expressions for the prediction of …
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Recent numerical techniques for differential equations arising in fluid flow problems
… ratio relaxation to retardation times parameter, Prandtl number, Schmidt number and the Deborah number is investigated. Also investigated is the influence of the ratio of relaxation to retardation times, Schmidt number and the Prandtl number on the skin friction, heat transfer rate and the mass …
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A Comparative Study of Two Solution Methods for Blade Momentum Equations Used in the Aerodynamic Analysis and Design of Wind Turbines
… tip-loss correction factor used is due to Prandtl and Glauert which is not always consistent with the physical behavior of the flow field near the tip. This research formulates a new more physically correct analytical expression for the tip losses and the results are compared with those …
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Magnetohydrodynamic Heat Transfer for Fusion Energy
… Aqueous potassium hydroxide is used as a high Prandtl number simulant fluid for molten salts and is flowed through a heated test section with 15 diameters of flow development within a uniform transverse magnetic field of up to 1.7 T (provided by a copper dipole) and Reynolds numbers up to …
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Convection and Magnetic Field Generation in Rotating Spherical Fluid Shells
… by convection shows a strong dependence on the Prandtl number P of the fluid. But this fact has received little attention in the past. Convection-driven dynamo action at Prandtl numbers larger than unity is studied with the goal to test the validity of the magnetostrophic approximation. The …
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Zum Dynamoeffekt in extern getriebenen Strömungen
… in den Modellgleichungen, der magnetischen Prandtl-Zahl und der Stärke des Energieinputs. Gefunden werden verschiedene Lösungstypen die von einem stationären Magnetfeld über periodische bis zu chaotischen Zuständen reichen. Die yugrundeliegenden Symmetrien werden beschrieben und die …
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Transport processes in a direct numerical simulation of turbulent channel flow
… The third subject involves the effect of Prandtl number on the transport of heat in turbulent flow between a hot wall and a cold wall. The effects of Prandtl number on the turbulent diffusivity of heat and on the dissipation of temperature fluctuations are presented. A prediction of the …
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Ventilation, stratification and flow instability driven by vertically distributed buoyancy sources
… a helical into an axisymmetric mode when the Prandtl number increases beyond a critical value. Both the roles of shear and buoyancy during the destabilisation are identified through an energy analysis which indicates that while (mean) shear work is usually a major source of perturbation …
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New mixing-length model for numerical solution of turbulent supersonic flows
… formula and following the ideas of Prandtl’s original mixing-length hypothesis, the effort has essentially been directed to classes of compressible flow problems where there exist large changes of density and Mach number. The new mixing-length model which has been found here is a …
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Heat Transfer In Tightly Packed Cylinder Arrays
… ranging from Reynolds number of 1k to 30k and Prandtl numbers of 0.7 and 10, are computationally modeled to develop a relationship between changing spacings and their influence on the heat transfer on the cylinders. The used model consists of a crossflow through 10 staggered rows of 2/3 …
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