Study on Model of Onset of Nucleate Boiling under Natural Circulation in Narrow Rectangular Channel by Using Unascertained Mathematics

Onset of nucleate boiling（ONB） is the key point of the flow boiling heat transfer process under natural circulation. According to the experimental data, the paper obtains the unascertained mathematical model of ONB’s heat flux in narrow rectangular channel based on the theory of unascertained mathematics. The paper analyzes the results of the calculation, then gets three sections: Available, Checkable, Rejectable. The result shows that the unascertained mathematical model is good at dealing with the unascertained information, can enhance the understanding of the experimental data, obtain an accurate and complete description on ONB’s heat flux.