Peristaltic flow of a Newtonian fluid through a porous medium in a vertical tube under the effect of a magnetic field

In this paper, we studied the effects of heat transfer and magnetic field with peristaltic flow of a viscous incompressible Newtonian fluid through a porous medium in a vertical tube under the assumptions of long wavelength and low Reynolds number. The closed form solutions of velocity field and temperature are obtained. The influence of various pertinent parameters on the flow characteristics, the temperature and the heat transfer coefficient are discussed through graphs

Dual nozzle aerodynamic and cooling analysis study

Geometric, aerodynamic flow field, performance prediction, and heat transfer analyses are considered for two advanced chamber nozzle concepts applicable to Earth-to-orbit engine systems. Topics covered include improvements to the dual throat aerodynamic and performance prediction program; geometric and flow field analyses of the dual expander concept; heat transfer analysis of both concepts, and engineering analysis of data from the NASA/MSFC hot-fire testing of a dual throat thruster model thrust chamber assembly. Preliminary results obtained are presented in graphs

A comparison with the three-zone model for flow boiling heat transfer in small diameter tubes

Flow boiling heat transfer experimental results, obtained in two stainless steel tubes of internal diameter 4.26 mm and 2.01 mm using R134a as the working fluid, indicate that the local heat transfer coefficient increases with heat flux and is independent of vapour quality when this is less than about 40% to 50% for the 4.26 mm tube and 20% to 30% for the 2.01 mm tube, conventionally interpreted as nucleate boiling. Above these quality values, the separate graphs merge into a single line for heat transfer coefficient decreasing with increasing vapour quality. The data in the apparently-nucleate boiling condition are compared with a recent state-of-the-art three-zone evaporation model for the confined bubble flow regime without a nucleate boiling contribution. The model predicts the experimental data reasonably well but does not predict correctly the trends for changing pressure and diameter. Some suggestions are made for improving the model. The comparisons made in this paper support the statements by the developers of the model and others that the application of conventional macro flow boiling correlations to micro tube flow boiling heat transfer may not necessarily have a sound physical basis

Measurement and Calibration of A High-Sensitivity Microwave Power Sensor with An Attenuator

In this paper, measurement and calibration of a high-sensitivity microwave power sensor through an attenuator is performed using direct comparison transfer technique. To provide reliable results, a mathematical model previously derived using signal flow graphs together with non-touching loop rule analysis for the measurement estimate (i.e. calibration factor) and its uncertainty evaluation is comparatively investigated. The investigation is carried out through the analysis of physical measurement processes, and consistent mathematical model is observed. Later, an example of Type-N (up to 18 GHz) application is used to demonstrate its calibration and measurement capability

Stagnation Point Flow of Non-Newtonian Fluid and Heat Transfer over a Stretching/Shrinking Sheet in a Porous Medium

The Study of stagnation Point flow and heat transfer Phenomena is considered in this paper. We used suitable similarity transformation to reduce governing partial differential equations into ordinary differential equations. These equation are non-linear differential equations which are solved numerically using Runge Kutta Fourth order method with efficient  shooting technique .The flow and temperature behaviour are analysed through graphs .The numerical values  of skin friction  coefficient and Local Nusselt are calculated, tabulated   and discussed. Keywords: Casson Fluid, Stagnation point flow, Heat transfer, Shrinking/streaching sheet, Skin Friction coefficient, Porous medium

Comparison of the Methods of Graphical Solution of Symbolic Sensitivity

Signal-flow graph (SFG) technique is a very useful tool for a hand analysis of a small and medium-size networks and/or subnetworks of large systems. Last days, the SFG's have been effectively used for the sensitivity solutions, too. This paper describes the comparison between two graph methods for derivation transfer function: the nullor modified Coates flow graph symbolic analysis and the transformation graphs for symbolic analysis. As is given, in some cases the transformation graphs are more useful thanks to their clarity than standard solving methods