Electrode design for electrohydrodynamic conduction pumping

An electrohydrodynamic conduction liquid pumping system includes a vessel configured to contain a liquid or a liquid/vapor therein. This vessel can be of a elongate conduit configuration, an elongate channel configuration or a liquid enclosure configuration. At least a single pair of electrodes are disposed in a spaced apart relation to each other on the vessel and configured to be oriented in the liquid. A power supply is coupled to the electrodes and operable to generate electric fields in between the pair of electrodes, the electric forces inducing a net liquid movement relative to the vessel. Various electrode designs are embraced within the concept of this invention

The pomeron and the multiperipheral model

In general this thesis is concerned with high energy elementary particle physics and in particular it discusses the interactions in the framework of the multiperipheral context. The first chapter is a general introduction to the field where different observables of interest, such as cross-section and multiplicity, are defined and discussed. In the second chapter after introducing different multi-particle production mechanisms, such as multiperipheral and diffractive models, we put more emphasis on the former and study different models of the type. The impact parameter space is a suitable place to work in, so we transform the multi-particle amplitude to this space and extract interesting results out of it in chapter 3. Especially the works of Henyey and Jedach-Turnau are emphasized in this chapter. We show that it is hard to reconcile the model with the experimentally observed radius of elastic scattering as a function of energy. The fourth chapter is about the interference diagrams of the multiperipheral model in the unitarity equation. As energy increases the number of such terms increases rapidly. We have estimated their effect in Henyey and Jedach-Tumau types of calculation and have added them to the 'standard' result. It is found that, as far as the radius is concerned, these extra terms (nl-l of them) do not make a significant contribution. In chapter five a modification of the basic multiperipheral amplitude is introduced in order to improve agreement with experiment. This successfully reproduces the known results

Optimation of cooled shields in insulations

A method to optimize the location, temperature, and heat dissipation rate of each cooled shield inside an insulation layer was developed. The method is based on the minimization of the entropy production rate which is proportional to the heat leak across the insulation. It is shown that the maximum number of shields to be used in most practical applications is three. However, cooled shields are useful only at low values of the overall, cold wall to hot wall absolute temperature ratio. The performance of the insulation system is relatively insensitive to deviations from the optimum values of the temperature and location of the cooling shields. Design curves for rapid estimates of the locations and temperatures of cooling shields in various types of insulations, and an equation for calculating the cooling loads for the shields are presented

INTERACTIONS BETWEEN BUBBLES IN CLOSE PROXIMITY UNDER UNIFORM AND NON-UNIFORM ELECTRIC FIELDS

ABSTRACT It is widely known that dielectrophoretic force can be harnessed to enhance the separation of liquid and vapor phases, with several known benefits in heat transfer enhancement. It has been shown that, when the electrode spacing and the bubble radius are of the same order of magnitude, the presence of the electric field can significantly deform the bubble, and this deformation can significantly affect the bubble's behavior. Additionally, the presence of a bubble can provide significant, local distortion of the electric field. Consequently, the existence of multiple bubbles in close proximity may generate interactions that serve to further affect bubble deformation and motion behavior. Of course, nucleate boiling involves the generation of several bubbles in close proximity, and it is useful to understand whether these interactions may favorably or adversely affect the potential for heat transfer enhancement. This numerical study simulates the behavior of two and three bubbles within an external, electric field. The geometric deformation of the bubbles due to the electric field and the distortion of the electric field due to the existence of the bubbles are both incorporated into the mathematical model. The numerical results provide information about the effect that one bubble can have on the others' motion, and also illustrate any tendencies of the bubbles to attract or repel each other when subject to various electric fields. Based on the numerical results, conclusions are drawn on the implications that the observed phenomenon may have on heat transfer enhancement applications

In-depth description of Electrohydrodynamic conduction pumping of dielectric liquids: physical model and regime analysis

In this work, we discuss the fundamental aspects of Electrohydrodynamic (EHD) conduction pumping of dielectric liquids. We build a mathematical model of conduction pumping that can be applied to all sizes, down to microsized pumps. In order to do this, we discuss the relevance of the Electrical Double Layer (EDL) that appears naturally on nonmetallic substrates. In the process, we identify a new dimensionless parameter related to the value of the zeta potential of the substrate-liquid pair, which quantifies the influence of these EDLs on the performance of the pump. This parameter also describes the transition from EHD conduction pumping to electro-osmosis. We also discuss in detail the two limiting working regimes in EHD conduction pumping: ohmic and saturation. We introduce a new dimensionless parameter, accounting for the electric field enhanced dissociation that, along with the conduction number, allows us to identify in which regime the pump operates.Ministerio de Ciencia, Innovación y Universidades PGC2018-099217-B-I0