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Impulse Breakdown of Liquids by Vasily Y. Ushakov download in ePub, pdf, iPad

After a thorongh analysis and

If there is only a single conducting particle between the electrodes, it will give rise to local field enhancement depending on its shape. When a bubble is formed, breakdown follows, either because of its elongation to a critical size or when it completely bridges the gap between the electrodes.

This mechanism is based on the

This mechanism is based on the experimental observations of extremely large currents just before breakdown. After a thorongh analysis and review of the data with the use of optical techniques, it is now clear that the understanding of the mechanism of liquid breakdown has advanced tremendously. From this equation, it can be seen that the breakdown strength depends on the initial size of the bubble which in turn is influenced by the hydrostatic pressure and temperature of the liquid.

They all try to account for the maximum obtainable breakdown strength only. These are explained briefly below. According to this theory the breakdown strength is inversely proportional to the stressed oil volume. Thermal Mechanism of Breakdown Another mechanism proposed to explain breakdown under pulse conditions is thermal breakdown.

The values of the Breakdown in Commercial Liquids containing solid impurities was found to be much less than the values for pure liquids. On the other hand, if only gas bubbles are present in the liquid. For example, in n-alkanes the breakdown strength was observed to depend on the chain length of the molecule. This theory does not take into account the production of the initial bubble and hence the results given by this theory do not agree well with the experimental results. All the theories discussed above do not consider the dependence of breakdown strength on the gap length.