With the increasing attention to environmental protection,it is still necessary to strictly control the oil evaporation loss from the IFRT(internal floating-roof tank)to the atmosphere.Upon using n-hexane as a represe...With the increasing attention to environmental protection,it is still necessary to strictly control the oil evaporation loss from the IFRT(internal floating-roof tank)to the atmosphere.Upon using n-hexane as a representative of light oil,the effects of the WDAs(wind deviation angles)on airflow distribution,the wind speed,the n-hexane vapor concentration,and the evaporation loss rate in the IFRT were investigated,and the mass transfer of the vapor-air was analyzed.The results are shown as follows:when the WDA is 0°,the vapor concentration in the gas space above the floating deck is the lowest;when the WDA is 22.5°,the oil evaporation loss rate is the largest;when the WDA is 45°,the vapor concentration is the highest,but the evaporation loss rate is the smallest.It is recommended to arrange the vent to the wind direction with an angle of 45°to reduce the evaporation loss and protect the atmospheric environment.展开更多
By analyzing turbulence data measured at two sites in coastal regions of Hangzhou bay,it is discovered that:(1)The turbulent intensity I_k is inversely proportional to the wind speed at lower speed.While at higher win...By analyzing turbulence data measured at two sites in coastal regions of Hangzhou bay,it is discovered that:(1)The turbulent intensity I_k is inversely proportional to the wind speed at lower speed.While at higher wind speed,it keeps basically to be constant.(2)Under the unstable conditions in the vicinity of sea shore,the dimensionless standard deviations of wind speed σ_k/U are constants basically,while in the inland,they can be described by the expressions similar to Panofsky(1977)models but with different constants.Under the stable conditions, they are constants when Z/L<0.2 and proportional to 1/3 power of Z/L for larger Z/L.(3) Near the coast,the variation of U/U with Z/L follows Businger(1971)model U/U =k/ (Z/L)very well not only under stable but also under unstable condition.Inland,it is coincident very well merely under the condition-1.0≤Z/L≤0.3.Out this range,the deviation is large.(4)The dispersion parameters can be described in the form recommended by Draxler (1976)but with different constants.Under the unstable condition,they can also be expressed as Briggs(1985)model with different constants.展开更多
The effects of baroclinic basic flow on a paralleled mesoscale disturbance development are investigated. By using the WKB method,two-dimensional perturbation equations with the anelastic approximation are analyzed.The...The effects of baroclinic basic flow on a paralleled mesoscale disturbance development are investigated. By using the WKB method,two-dimensional perturbation equations with the anelastic approximation are analyzed.The result indicates that the symmetric development of a mesoscale disturbance is due to the in- homogeneous thermal wind deviations and unstationality of the basic field.展开更多
基金the National Natural Science Foundation of China(No.51574044)the Key Research and Development Program of Jiangsu Province(Industry Foresight and Common Key Technology)(No.BE2018065)+1 种基金the Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX182630)the Nature Science Foundation of Jiangsu Province(No.BK20150269)。
文摘With the increasing attention to environmental protection,it is still necessary to strictly control the oil evaporation loss from the IFRT(internal floating-roof tank)to the atmosphere.Upon using n-hexane as a representative of light oil,the effects of the WDAs(wind deviation angles)on airflow distribution,the wind speed,the n-hexane vapor concentration,and the evaporation loss rate in the IFRT were investigated,and the mass transfer of the vapor-air was analyzed.The results are shown as follows:when the WDA is 0°,the vapor concentration in the gas space above the floating deck is the lowest;when the WDA is 22.5°,the oil evaporation loss rate is the largest;when the WDA is 45°,the vapor concentration is the highest,but the evaporation loss rate is the smallest.It is recommended to arrange the vent to the wind direction with an angle of 45°to reduce the evaporation loss and protect the atmospheric environment.
文摘By analyzing turbulence data measured at two sites in coastal regions of Hangzhou bay,it is discovered that:(1)The turbulent intensity I_k is inversely proportional to the wind speed at lower speed.While at higher wind speed,it keeps basically to be constant.(2)Under the unstable conditions in the vicinity of sea shore,the dimensionless standard deviations of wind speed σ_k/U are constants basically,while in the inland,they can be described by the expressions similar to Panofsky(1977)models but with different constants.Under the stable conditions, they are constants when Z/L<0.2 and proportional to 1/3 power of Z/L for larger Z/L.(3) Near the coast,the variation of U/U with Z/L follows Businger(1971)model U/U =k/ (Z/L)very well not only under stable but also under unstable condition.Inland,it is coincident very well merely under the condition-1.0≤Z/L≤0.3.Out this range,the deviation is large.(4)The dispersion parameters can be described in the form recommended by Draxler (1976)but with different constants.Under the unstable condition,they can also be expressed as Briggs(1985)model with different constants.
文摘The effects of baroclinic basic flow on a paralleled mesoscale disturbance development are investigated. By using the WKB method,two-dimensional perturbation equations with the anelastic approximation are analyzed.The result indicates that the symmetric development of a mesoscale disturbance is due to the in- homogeneous thermal wind deviations and unstationality of the basic field.
