The characteristic of flow and heat transfer of A12Oa-water nanofluids flowing through a horizontal ventilated cavity is investigated numerically. The bottom wall is subjected to a linearly varying increasing heating ...The characteristic of flow and heat transfer of A12Oa-water nanofluids flowing through a horizontal ventilated cavity is investigated numerically. The bottom wall is subjected to a linearly varying increasing heating temperature profile, whereas the other boundaries are assumed to be thermally insulated. The enclosure is cooled by an injected or sucked imposed flow. The simulations are focused specifically on the effects of different key parameters such as Reynolds number, 200 〈 Re 〈 5,000, nanoparticles concentration, 0 〈 φ 〈 0.1, and mode of imposed flow, on the flow and thermal patterns and heat transfer performances. The findings demonstrate clearly the positive role of the nanoparticles addition on the improvement of the heat transfer rate and the mean temperature within the cavity. Also, the results presented show that, the suction mode is more favorable to the heat transfer in comparison with the case of the injection mode. The cooling efficiency is found to be more pronounced by applying the suction mode.展开更多
By means of reasonable assumption and mathematical derivation, a theoretic expression of flow rate for a single fracture with linearly varying width was obtained. The mathematical derivation was based on the cubic law...By means of reasonable assumption and mathematical derivation, a theoretic expression of flow rate for a single fracture with linearly varying width was obtained. The mathematical derivation was based on the cubic law and the new theoretic expression was an extention of traditional parallel plate model. This study may help to analyze seepage in fractured rock mass.展开更多
文摘The characteristic of flow and heat transfer of A12Oa-water nanofluids flowing through a horizontal ventilated cavity is investigated numerically. The bottom wall is subjected to a linearly varying increasing heating temperature profile, whereas the other boundaries are assumed to be thermally insulated. The enclosure is cooled by an injected or sucked imposed flow. The simulations are focused specifically on the effects of different key parameters such as Reynolds number, 200 〈 Re 〈 5,000, nanoparticles concentration, 0 〈 φ 〈 0.1, and mode of imposed flow, on the flow and thermal patterns and heat transfer performances. The findings demonstrate clearly the positive role of the nanoparticles addition on the improvement of the heat transfer rate and the mean temperature within the cavity. Also, the results presented show that, the suction mode is more favorable to the heat transfer in comparison with the case of the injection mode. The cooling efficiency is found to be more pronounced by applying the suction mode.
基金supported by the National Basic Research Program of China(2009CB219605)the National Natural Science Foundation of China(41074040)
文摘By means of reasonable assumption and mathematical derivation, a theoretic expression of flow rate for a single fracture with linearly varying width was obtained. The mathematical derivation was based on the cubic law and the new theoretic expression was an extention of traditional parallel plate model. This study may help to analyze seepage in fractured rock mass.
