An Experimental Study On The Self-oscillation And Its Application

Self-oscillation initiated by Helmholtz resonance chamber with different configuration under different waterpower parameters is introduced in the paper. The influence on the heat transfer enhancement of the heat exchanger by applying resonance chamber is discussed in detail. Several important conclusions based on the experiment are given. Self-oscillation can be generated under suitable configuration and waterpower parameters. For the same configuration resonance chamber, the intensity of the self-oscillation is changed by the waterpower parameters. When the pressure increases, self-oscillation intensity will increase. By applying the self-oscillation generated by the resonance chamber to the heat exchanger, and when the self-oscillation intensity achieves a certain degree, heat transfer will be enhanced. The heat transfer enhancement is different under different oscillator. There is the optimum oscillation intensity under which the heat transfer coefficient will be increased by about 30 percent. The change of outlet structure size of a resonance chamber shows little effect on the strength of heat transfer: the pressure of the optional heat transfer coefficient always is between 0.4MPa and 0.6MPa, and the optional heat transfer coefficient is enhanced by 30 percent or so. This conclusion is very important when we use the resonance chamber to a heat exchanger in engineering projects, especially for reforming the existing heat exchangers.Furthermore, this paper includes numerical calculation of water-steam phase transition. We get several useful conclusions on isobaric evaporation, isothermal flash, isobaric condensation, isothermal compressed condensation. An analysis on the micro-layer evaporation model is also discussed in the paper.