The flow pattern behaviour of falling liquid film over three horizontal cylinders was evaluated.These flows can take three forms:discrete droplets,individual jets,and continuous sheet,and special attention is paid to ...The flow pattern behaviour of falling liquid film over three horizontal cylinders was evaluated.These flows can take three forms:discrete droplets,individual jets,and continuous sheet,and special attention is paid to the effects of the physical properties and geometrical parameters of the first two forms(droplets and jets) because these forms are more important in heat-transfer behaviour and less research has been published for these forms,The flow modes and experimental results were successfully compared with previous experimental literatures,and also the effects of liquid flow rate,tube diameter,and tube spacing on departure site spacing,in both drop and jet modes,were evaluated in the low Galileo number and high viscosity fluid(cooking oil),to help developing criteria for determining falling film modes and their transitions,and to understand the heat transfer characteristics associated with each mode.展开更多
This paper analyzes the physicochemical properties of supercritical C02, the characteristic of shale gas and shale gas reservoirs. The technologies of drilling, production, fracturing using the supercritical CO2 in sh...This paper analyzes the physicochemical properties of supercritical C02, the characteristic of shale gas and shale gas reservoirs. The technologies of drilling, production, fracturing using the supercritical CO2 in shale gas explo- ration are proposed, to increase the penetration rate, decrease the damage to formation while fracturing, and enhance the recovery of shale gas. It is believed that the huge economic benefits of shale gas exploration with the supercritical CO2 fluid will be obtained, and it also can initiate a new technology field of CO2 in the petroleum engineering.展开更多
Based on the tortuous-expanding path/channel model,a micro-mechanism model for porous media is developed.The proposed model is expressed as a function of tortuosity,porosity,resistance coefficient,and fluid properties...Based on the tortuous-expanding path/channel model,a micro-mechanism model for porous media is developed.The proposed model is expressed as a function of tortuosity,porosity,resistance coefficient,and fluid properties.Every parameter in the proposed model has clear physical meaning.The results show that the model predictions are ingood agreement with those from the existing experimental data.展开更多
Convective heat transfer coefficient is one of the most vital parameters which reveals the thermal efficiency of a pipe flow.To obtain such coefficients for problems with variable pipe wall temperature,numerical itera...Convective heat transfer coefficient is one of the most vital parameters which reveals the thermal efficiency of a pipe flow.To obtain such coefficients for problems with variable pipe wall temperature,numerical iterative methods should be used which could be time-consuming and less accurate.In this paper,thermophysical properties of fluids are assumed to be constant.We define a variable related to the temperature gradient of the pipe wall and study the varying law of the local coefficient.Then,a sample-based scheme is proposed to avoid the calculation of a time-consuming problem in the use of solutions with low computing cost.To verify its accuracy,several problems in normal circle pipes with variable factors,such as the various temperatures of the pipe wall,the different radius of the pipe,and various velocities of fluid flow,are well resolved.Meanwhile,its validity in a convergent pipe is also studied.From the obtained results,the high accuracy and efficiency of the proposed scheme can be confirmed.Therefore,the proposed scheme for determining the convective heat transfer coefficient has great potential in engineering problems.展开更多
基金supported by New Product Development of Small and Medium Business Administration(SMBA)funded by the Ministry of Education,Science and Technology (No. 2011-0021376) through the Basic Science Program of the National Research Foundation of Korea(NRF)
文摘The flow pattern behaviour of falling liquid film over three horizontal cylinders was evaluated.These flows can take three forms:discrete droplets,individual jets,and continuous sheet,and special attention is paid to the effects of the physical properties and geometrical parameters of the first two forms(droplets and jets) because these forms are more important in heat-transfer behaviour and less research has been published for these forms,The flow modes and experimental results were successfully compared with previous experimental literatures,and also the effects of liquid flow rate,tube diameter,and tube spacing on departure site spacing,in both drop and jet modes,were evaluated in the low Galileo number and high viscosity fluid(cooking oil),to help developing criteria for determining falling film modes and their transitions,and to understand the heat transfer characteristics associated with each mode.
基金Key Project of Chinese National Programs for Fundamental Research and Development(973 Program) (No. 2010CB226704)Chinese National Natural Science Foundation (No. 51034007 )+1 种基金the China National Petroleum Corporation Key Project Foundation (No. 2011A-4205)China Postdoctoral Science Foundation(No. 2011M500492)
文摘This paper analyzes the physicochemical properties of supercritical C02, the characteristic of shale gas and shale gas reservoirs. The technologies of drilling, production, fracturing using the supercritical CO2 in shale gas explo- ration are proposed, to increase the penetration rate, decrease the damage to formation while fracturing, and enhance the recovery of shale gas. It is believed that the huge economic benefits of shale gas exploration with the supercritical CO2 fluid will be obtained, and it also can initiate a new technology field of CO2 in the petroleum engineering.
基金Supported by National Nature Science Foundation of China under Grant Nos.40672156 and D0624005the National Basic Research Program (973 Program) under Grant No.2006CB202200
文摘Based on the tortuous-expanding path/channel model,a micro-mechanism model for porous media is developed.The proposed model is expressed as a function of tortuosity,porosity,resistance coefficient,and fluid properties.Every parameter in the proposed model has clear physical meaning.The results show that the model predictions are ingood agreement with those from the existing experimental data.
基金the National Natural Science Foundation of China(Grant No.12072103)the Fundamental Research Funds for the Central Universities(Grant No.B200202126)+2 种基金the Natural Science Foundation of Jiangsu Province(Grant No.BK20190073)the State Key Laboratory of Acoustics,Chinese Academy of Sciences(Grant No.SKLA202001)the China Postdoctoral Science Foundation(Grant Nos.2017M6I 1669 and 2018T110430).
文摘Convective heat transfer coefficient is one of the most vital parameters which reveals the thermal efficiency of a pipe flow.To obtain such coefficients for problems with variable pipe wall temperature,numerical iterative methods should be used which could be time-consuming and less accurate.In this paper,thermophysical properties of fluids are assumed to be constant.We define a variable related to the temperature gradient of the pipe wall and study the varying law of the local coefficient.Then,a sample-based scheme is proposed to avoid the calculation of a time-consuming problem in the use of solutions with low computing cost.To verify its accuracy,several problems in normal circle pipes with variable factors,such as the various temperatures of the pipe wall,the different radius of the pipe,and various velocities of fluid flow,are well resolved.Meanwhile,its validity in a convergent pipe is also studied.From the obtained results,the high accuracy and efficiency of the proposed scheme can be confirmed.Therefore,the proposed scheme for determining the convective heat transfer coefficient has great potential in engineering problems.
