High strength AC electric fields generate a body force on a dielectric medium confined between two electrodes. The body forces are due to two factors. First is the variation in permittivity across an interface such as liquid–air present between the electrodes. The second is a change in the dielectric property of the medium due to a variation in the thermodynamic properties such as temperature. The height rise of a dielectric medium between two electrodes is one of the consequences of these electrical body forces and is used here as a comparatively simple way to study these forces. In an aqueous solution with finite conductivity, the effects of the frequency of the supplied voltage source and the temperature change due to Joule heating on height rise have never been studied in this context. This study focuses on systems where the contributions of surface forces are negligible and highlights the interplay between solution conductivity, applied electric field, and the solution height/temperature behavior. Using a generic thermodynamic model for an aqueous solution under the application of an alternating current electric field, it is shown that for low conductivity solutions the resulting temperature and height rise change weakly with the applied field frequency and strongly with the applied electric field. For higher conductivity solutions, the behavior becomes more complex with respect to the electric field strength. As compared to Pellat’s original model, the height rise varies from strongly suppressed to enhanced.

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In this paper, the effect of electric fields on phase equilibria through polarization is investigated. A relation is derived for the chemical potential of a system, where the electric field is localized over a liquid phase mixture in equilibrium with a vapor phase mixture. This relation is then applied to a water−ethanol mixture to explore the effect of polarization-based electric fields on the liquid phase composition. It is observed that the quadratic dependence on electric field strength produces little effect below field strengths of approx. 10 MV/m. However, above this field strength, the mole fraction of water in the liquid phase grows rapidly, increasing by a factor of 8 for a water vapor phase fraction of 0.2 and a field strength of 500 MV/m, which approaches the dielectric breakdown strength of water. Nonetheless, this field strength could be achievable with microfluidic experimental setups.

A novel method of measuring the influence of high electric fields on the Raman scattering of fluids is introduced, which can help understand various interactions of a fluid with the high electric field. The microfluidic chip can impose highly controlled, uniform electric fields across the measurement volume with blocked electrodes, eliminating spurious reactions at the electrode surface. The developed methodology and the experimental setup are utilized to examine the effect of the electric field on three of the stretching vibrations of ethanol in water–ethanol mixtures with varying concentrations of ethanol and effective electric fields up to 1.0MV/m. The increase in the electric field is seen to broadly decrease the intensity of Raman scattering due to a decrease in the polarizability of the ethanol molecules. Although this effect is uniform for all water-ethanol mixtures, it reduces in mixtures with high weight-fractions of water because of the already reduced polarizability of an ethanol molecule due to hydrogen bonding. The combined effect of hydrogen bonding and increase in temperature due to the alternating high electric field even results in an increase in the magnitude of peak intensity for relatively low-weight fractions of ethanol.

This paper describes a vehicle-level simulation model for climate control and powertrain cooling developed and currently utilized at GM. The tool was developed in response to GM's need to speed vehicle development for HVAC and powertrain cooling to meet world-class program execution timing (18 to 24 month vehicle development cycles). At the same time the simulation tool had to complement GM's strategy to move additional engineering responsibility to its HVAC suppliers. This simulation tool called "e-Thermal" was quickly developed and currently is in widespread (global) use across GM. This paper describes GM's objectives and requirements for developing e-Thermal. The structure of the tool and the capabilities of the simulation tool modules (refrigeration, front end airflow, passenger compartment, engine, transmission, Interior air handling …) is introduced. Model data requirements and GM's strategy for acquiring component data are also described. The paper includes an example of a typical application of the tool with sample output from the simulation and some comparison to actual test data from a vehicle under the same test scenario.