Effect of magnetic field on temperature profile and flame flow characteristics of micro flame using Talbot interferometer

Optik ◽  
2018 ◽  
Vol 168 ◽  
pp. 817-826 ◽  
Author(s):  
Shilpi Agarwal ◽  
Chandra Shakher
2017 ◽  
Vol 829 ◽  
pp. 328-344 ◽  
Author(s):  
V. D. Borisevich ◽  
E. P. Potanin ◽  
J. Whichello

A model of a laminar viscous conducting flow, near a dielectric disc in a uniform magnetic field and in the presence of external rotation, is considered, where there is a uniform suction and an axial temperature gradient between the flow and the disc’s surface. It is assumed that the parameters of the suction or the magnetohydrodynamic (MHD) interaction are such that the nonlinear inertial terms, related to the circulation flow, are negligible in the differential equations of the MHD boundary layer on a rotating disc. Analysis of the motion and energy equations, taking the dependence of density on temperature into account, is carried out using the Dorodnitsyn transformation. The exact analytical solution for the boundary layer and heat transfer equations is obtained and analysed, neglecting the viscous and Joule dissipation. The dependence of the flow characteristics in the boundary layer on the rate of suction and the magnetic field induction is studied. It is shown that the direction of the radial flow in the boundary layer on a disc can be changed, not only by variation of the ratio between the angular velocities in the external flow and the boundary layer, but also by changing the ratio of the temperatures in these two flows, as well as by varying the hydrodynamic Prandtl number. The approximate calculation of a three-dimensional flow in a rotating cylinder with a braking disc (or lid) is carried out, demonstrating that a magnetic field slows the circulation velocity in a rotating cylinder.


2018 ◽  
Vol 16 (6) ◽  
pp. 385-390
Author(s):  
Shikha BINWAL ◽  
Jay K JOSHI ◽  
Shantanu Kumar KARKARI ◽  
Predhiman Krishan KAW ◽  
Lekha NAIR ◽  
...  

A floating emissive probe has been used to obtain the spatial electron temperature (Te) profile in a 13.56 MHz parallel plate capacitive coupled plasma. The effect of an external transverse magnetic field and pressure on the electron temperature profile has been discussed. In the un-magnetised case, the bulk region of the plasma has a uniform Te. Upon application of the magnetic field, the Te profile becomes non-uniform and skewed.  With increase in pressure, there is an overall reduction in electron temperature. The regions adjacent to the electrodes witnessed a higher temperature than the bulk for both cases. The emissive probe results have also been compared with particle-in-cell simulation results for the un-magnetised case.


2021 ◽  
Author(s):  
Szym on Buhajczuk

A numerical study into magneto-aerodynamic bleed control systems has been undertaken with the intent of improving the shock swallowing ability of high speed engine intakes. Past research has shown that bleed slots effectively remove sufficient mass flow of air from the system to permit shocks to be swallowed. A magnetic field's influence on a charged boundary layer creates a possibility of sealing a bleed slot when not needed. 2D bleed slots were modeled using structured grids for use with the FLUENT CFD solver. User defined functions were written to simulate charge generation and magnetic field forces. Solutions revealed that bleed slot angles, free stream Mach numbers, pressure ratios, boundary layer displacement thickness, field strength and field position all affect how the system performs. Results have shown that a properly positioned magnetic field can reduce sonic flow coefficients up to 88%, thus justifying further research and investment in wind tunnel experiments.


2021 ◽  
pp. 2150157
Author(s):  
Yu-Ming Chu ◽  
Rasoul Moradi ◽  
Amir Musa Abazari

The thermal efficiency of the heat exchanger is substantial in chemical and mechanical systems. The presence of the non-homogeny magnetic field considerably enhances the heat rate of nanofluid stream. In this exploration, the presence of the non-uniform magnetic intensity on the heat rate of nanofluid stream is noted inside the 180[Formula: see text] elbow pipe. FVM is used to model the flow characteristics and temperature distribution through the 180[Formula: see text] elbow pipe. Our major focus is to demonstrate the main influences of the non-uniform FHD on flow stream and heat transfer of nanofluid in various inlet velocities and magnetic intensities. Achieved outcomes display that growing the magnetic intensity from 1e + 6 to 4e + 6 enhances the average Nusselt number about 30%. Our findings show that increasing the inlet velocity to Re = 100 decreases the magnetic effects about 17% on the heat transfer growth.


2020 ◽  
Vol 98 (2) ◽  
pp. 191-197 ◽  
Author(s):  
Hina Sadaf ◽  
S. Nadeem

This paper investigates fluid motion generated by cilia and a pressure gradient in a curved channel. The flow analysis is carried out in the presence of heat transfer and radial magnetic field. The leading equations are simplified under the familiar suppositions of large wavelength and small Reynolds number approximations. An exact solution has been developed for the velocity profile. The flow characteristics of the viscous fluid are computed in the presence of cilia and metachronal wave velocity. The effects of several stimulating parameters on the flow and heat transfer are studied in detail through graphs. It is found that symmetry of the velocity profile is broken owing to bending of the channel. The radially varying magnetic field decreases the velocity field, but near the left ciliated wall it induces the opposite behavior. It is also found that velocity profile increases due to increase in buoyancy forces throughout the domain. Numerical consequences for velocity profile are also accessible in the table for diverse values of the physical parameters.


2018 ◽  
Vol 145 ◽  
pp. 03009 ◽  
Author(s):  
Todor M. Mishonov ◽  
Albert M. Varonov ◽  
Nedeltcho I. Zahariev ◽  
Rositsa V. Topchiyska ◽  
Boian V. Lazov ◽  
...  

The sharp almost step like increase the temperature in the transition region (TR) between chromosphere and solar corona is well-known from decades; for first time we are giving a detailed magnetohydrodynamic (MHD) calculation of the height dependence of the temperature. The width of the transition region is evaluated by maximal value of the logarithmic derivative of the temperature. At fixed heating, only MHD can give such a narrow width and in such sense, even the qualitative agreement with the observational data, gives the final verdict what the heating mechanism of the solar corona is. Static profiles of the temperature and wind velocity are calculated for static frequency dependent spectral density of the incoming MHD waves; no time dependent computer simulations. At fixed spectral density of MHD waves, the MHD calculation predicts height dependence of the non-thermal broadening of spectral lines and its angular dependence. For illustration is used one dimensional approximation of completely ionized hydrogen plasma in weak magnetic field, but it is considered that the width of the TR is weakly dependent with respect of further elaboration. The analyzed MHD calculation is a numerical confirmation of the qualitative concept of self-induced opacity of the plasma with respect to MHD waves. The plasma viscosity strongly increases with the temperature. Heated by MHD waves, plasma increases the wave absorption and this positive feedback leads to further heating. The static temperature profile is a result of a self-consistent calculation of propagation of MHD wave through the static background of wind and temperature profile. The numerical method allows consideration of incoming MHD waves with an arbitrary spectral density. Further elaboration of the method are briefly discussed: influence of second viscosity in the chromospheric part of the TR, influence of the magnetic field on the coronal side of the TR and investigation of such type effects on the width of the TR.


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