円形および楕円形ノズルからの不足膨張噴流に関する解析的研究

The supersonic jet issuing from circular and elliptic exit of convergent-divergent nozzle has been investigated by rainbow schlieren deflectometry and modified linearized model. In experimentally, a design Mach number of 1.5 followed by a cylindrical duct with an inner diameter of 10 mm, and length of 50 mm are considered to measure the density, internal flow features of jet combing with the computed tomography. In theoretically, a modified vortex sheet model taking viscosity into account has been proposed. The properties of Bessel’s and Mathieu functions with the first Fourier mode of eigenvalues are executed for the individual exit geometry to evaluate the explicit solution of inviscid and viscous jet separately. The embodied results of density, shock-cell spacing, and size measuring have also been examined theoretically. In comparison, the accomplished yields are shown better agreement with published data due to the aspect ratios, nozzle pressure ratios and design Mach number arbitrarily.北九州市立大

Unsteady Viscous Incompressible Bingham Fluid Flow through a Parallel Plate

Numerical investigation for unsteady, viscous, incompressible Bingham fluid flow through parallel plates is studied. The upper plate drifts with a constant uniform velocity and the lower plate is stationary. Both plates are studied at different fixed temperatures. To obtain the dimensionless equations, the governing equations for this study have been transformed by usual transformations. The obtained dimensionless equations are solved numerically using the explicit finite difference method (FDM). The studio developer Fortran (SDF) 6.6a and MATLAB R2015a are both used for numerical simulations. The stability criteria have been established and the system is converged for Prandtl number P r ≥ 0.08 with Δ Y = 0.05 and Δ τ = 0.0001 as constants. As a key outcome, the steady-state solutions have been occurred for the dimensionless time τ   =   4.00 The influence of parameters on the flow phenomena and on shear stress, including Nusselt number, are explained graphically. Finally, qualitative and quantitative comparison are shown