Free Convection Flow Of Water Research Articles

Temperature measurement in laminar free convective flow using digital holography

A method for measurement of temperature in laminar free convection flow of water is presented using digital holographic interferometry. The method is relatively simple and fast because the method uses lensless Fourier transform digital holography, for which the reconstruction algorithm is simple and fast, and also the method does not require use of any extra experimental efforts as in phase shifting. The quantitative unwrapped phase difference is calculated experimentally from two digital holograms recorded in two different states of water--one in the quiescent state, the other in the laminar free convection. Unknown temperature in laminar free convection is measured quantitatively using a known value of temperature in the quiescent state from the unwrapped phase difference, where the equation by Tilton and Taylor describing the variation of refractive index of water with temperature is used to connect the phase with temperature. Experiments are also performed to visualize the turbulent free convection flow.

Free convection effects on the flow of water at 4°C past a semi-infinite inclined plate

Free convection flow of water at its maximum density past a semi-infinite inclined plate has been studied by using an implicit-finite difference technique. The steady-state velocity and temperature profiles, local and average skin friction and the Nusselt number are shown graphically. It is observed that velocity decreases owing to a fall in temperature of water from 20°C to 4°C.

Free convection flow of water near 4 °C past a moving plate

In the present study the unsteady free convection flow of water near 4 ∘C in the laminar boundary layer over a vertical moving porous plate is investigated. The effect of the suction/injection parameter at the plate on the velocity is considered. The momentum equation is solved numerically by a fourth-order Runge-Kutta scheme. The numerical results which are obtained for the flow are shown graphically.

Experimental analysis of a confined transitional plume with respect to subgrid-scale modelling

Free convection flow of water induced by a small prismatic heat source in a confined space is studied in the present paper. The forcing of the flow is in the range of Rayleigh numbers where a spatial transition from laminar to turbulent flow can be observed.Velocity measurements were performed by means of Particle Tracking Velocimetry (PTV ) . From the velocity data a resolved and a subgrid field is obtained by means of spatial filtering. These data are analysed with respect to modelling consequences in Large-Eddy Simulation (LES) , constituting an a priori test.Astatistically steady flow has been obtained with a converged temporal mean and standard deviation as function of space. A low correlation of time mean model stresses with exact stresses is found. In the transitional region the inter-scale kinetic energy transfer, taken over a wavenumber corresponding to the laminar plume width, is found to possess a relative large standard deviation. In this region backscatter and forward scatter of kinetic energy, with respect to the mentioned wavenumber, are of equal importance. Application of a dynamic model to the filtered data yields a qualitative good representation of the exact inter-scale kinetic energy transfer.

Hydromagnetic Free Convection Flow Over an Inclined Plate Caused by Solar Radiation

This note discusses steady, laminar, two-dimensional, free convection flow of water up an iclined flat plate in the presence of a uniform transverse magnetic field and solar radiation. This flow situation has possible application in natural water bodies; crystal growth; solar-energy collectors with direct solar-energy collection and storage using absorbing fluids such as ammonia, carbon dioxide, and water; geothermal reservoirs, solar heating systems, packed-bed catalytic reactors, and cooling of nuclear reactors

Magnetohydrodynamic free convection flow of water at 4°C through a porous medium

MHD forced and free convection flow of water at 4°C through a porous medium in the presence of a uniform transverse magnetic field is considered. A family of solutions of the coupled non-linear equations is presented using shooting numerical techniques for two point boundary value problems. Velocity and temperature profiles are shown for different values of the parameters Ha 2/Re, Gr/Re 2 and K.

Transient free convection flow of water at 4°C past a semi-infinite vertical plate

Transient free convection flow of water at 4°C past an isothermal semi-infinite vertical plate, when its density is maximum, is analysed by employing an explicit finite-difference technique. The transient velocity and temperature, the average skin-friction and the average Nusselt number are shown graphically for Prandtl number Pr=11.4 (4°C) and 7.0 (20°C). It has ben observed that when the density of water is maximum, it takes more time to reach its steady state. Also the average skin-friction decreases considerably when the water is at 4°C, as compared to that at 20°C. The average Nusselt number increases at small values of time and decreases at large values of time when the water is at 4°C.

Transient free convection in cold water past an infinite vertical porous plate

A finite-difference solution of the transient free convection flow of water near 4°C past an infinite vertical porous plate has been carried out. The most appropriate relation for the density in terms of the temperature, as derived by Gebhart and Mollendorf, is employed. It has been observed that, when the buoyancy force is in the upward direction, the velocity profiles are positive and opposite to those in the case where the buoyancy force is in the downward direction. Also, the skin friction is more when the buoyancy force is in the upward direction than when the buoyancy force is in the downward direction.

Free convection flow op Water at 4° C past a semi-infinite porous plate

Local similarity solutions of the free convection flow of water at 4°C past a semi-infinite porous plate have been obtained numerically using shooting techniques for two-point boundary value problems. Velocity profiles are Gr shown for different values of parameter -where Gr Grashof number and Re, Re2 Reynolds number.

Free-convection flow of water at 4�C past an infinite vertical porous plate with constant heat flux

An analysis of the two-dimensional flow of water at 4°C past an infinite porous plate is presented, when the plate is subjected to a normal suction velocity and the heat flux at the plate is constant. Approximate solutions are derived for the velocity and temperature fields and the skin-friction. The effects ofG (Grashof number) andE (Eckert number) on the velocity and temperature fields are discussed.

Free convection flow of water at 4°C passing an infinite porous plate with constant suction in a rotating system

In this work an analysis of steady free convection flow of water at 4°C passing a vertical infinite porous plate in a rotating system is considered. Approximate solutions for the coupled nonlinear equations are obtained for the velocity and the temperature. The effect of E′ (Eckman number) is discussed, when P (Prandtl number)=11.4, which corresponds to water at 4°C.

Free convection flow of water at 4° C past an infinite porous plate with constant suction and free stream velocity

An analysis of the two-dimensional flow of water at 4° C past an infinite porous plate is presented under the following conditions : (i) The suction velocity normal to the plate is constant, (ii) the free stream velocity is constant, (iii) the plate temperature is constant, (iv) the difference between the tempera¬ ture of the plate and the free stream is such that to have free convection currents. Approximate solutions for the coupled non linear equations are obtained for the velocity and temperature field and for the rate of heat transfer. The effects of G (Grashof number) on the velocity and the rate of heat transfer are discussed.

Laminar free convection flow of water at 4°C from a vertical plate with variable wall temperature

Laminar free convection flow of water at 4°C from a vertical plate with variable wall temperature

Free convection flow of water at 4°C on vertical and horizontal plates

Free convection flow of water at 4°C on vertical and horizontal plates