Electric Field Heat Transfer Augmentation During Condensation of Nonconducting Fluids on a Horizontal Surface
Experiments were carried out to determine the heat transfer coefficient during condensation on the underside of a horizontal plate with and without an electric field applied perpendicular to the plate. An expression is presented, correlating the augmentation of the heat transfer coefficient to the most unstable wavelength of the electrohydrodynamical instability of the condensate-vapor interface.
A new set of correlations for EHD enhanced condensation heat transfer of tubular systems
Abstract An improved set of correlations for evaluating the heat transfer coefficient of EHD assisted condensation heat transfer for tubular systems is presented in this paper. The correlations were developed by curve fitting a wide range of experimental data and then optimising the empirical constants so that the percentage deviation is less than ±30%. The experimental data was classified in four categories: (I) condensation outside horizontal smooth tubes, (II) condensation inside horizontal smooth tubes, (III) condensation outside vertical tubes and (IV) condensation inside vertical tubes. The experimental data in each category included results obtained using various refrigerants and various electrode systems. The improved correlations were used to predict a total of 166 experimental data points. A comprehensive literature review of all available correlations for EHD assisted condensation heat transfer is also described in this paper. Two correlations that were identified to be simple were used to predict the above-mentioned data bank. These are the correlations of Choi and Reynolds and Didkovesky and Bologa. The Choi and Reynolds correlation was found to successfully predict heat transfer rates of condensation outside horizontal and vertical tubes and of condensation inside vertical tubes when high intensity electric field is applied. However, the Didkovesky and Bologa correlation was found to successfully predict only the results of condensation heat transfer outside vertical surfaces.
Investigations of dielectric gratings using electrodynamic models based on volume integral equations
Eigenmodes of planar and cylindrical dielectric gratings (DGs) and electromagnetic wave scattering from multiplayer DGs are investigated. The DG characteristics are calculated using numerical-analytical solution of integral equations (IEs).