To improve the comfortability and safety of aircraft,the demand of rectangular submerged inlets(RSIs)with low resistance is proposed to increase the inlet flow rate of ram air. A theoretical model is built to numerica...To improve the comfortability and safety of aircraft,the demand of rectangular submerged inlets(RSIs)with low resistance is proposed to increase the inlet flow rate of ram air. A theoretical model is built to numerically analyze the effects of geometric parameters on the inlet mass flow rate of RSIs. The geometric parameters in question here encompass the aspect ratio of 2—4,the ramp angle of 6°—7°,the characteristic parameter of the throat of 0.20 —0.30,the ramp length of 939—1 337 mm,and the cone angle of 0° —3°. Simulation results demonstrate that the mass flow rate(MFR)is positively correlated with the aspect ratio,ramp angle,ramp length,and cone angle,and negatively correlated with characteristic parameter of the throat. Within the range of the geometric parameters considered,the RSI with the aspect ratio of 3,the ramp angle of 6°,the characteristic parameter of the throat of 0.20,the ramp length of 1 337 mm,and the cone angle of 3° obtains the largest MFR value of about 2.251 kg/s.展开更多
A novel semi-submersible platform is proposed for 5 MW wind turbines.This concept focuses on an integrated system formed by combining porous shells with a semi-submersible platform.A coupled aerodynamic–hydrodynamic...A novel semi-submersible platform is proposed for 5 MW wind turbines.This concept focuses on an integrated system formed by combining porous shells with a semi-submersible platform.A coupled aerodynamic–hydrodynamic–mooring analysis of the new system is performed.The motion responses of the novel platform system and the traditional platform are compared.The differences in hydrodynamic performance between the two platforms are also evaluated.The influence of the geometric parameters(porosity,diameter,and wall thickness)of porous shells on the motion response behavior of the new system is studied.Overall,the new semi-submersible platform exhibits superior stability in terms of pitch and heave degrees of freedom,demonstrating minimal effects on the motion response in the surge degree of freedom.展开更多
A compound hydrocyclone is a new strategy for oil-water separation. It is based on the study of static and dynamic hydrocyclones. In this paper are introduced its geometric traits and separation mechanism. Experiments...A compound hydrocyclone is a new strategy for oil-water separation. It is based on the study of static and dynamic hydrocyclones. In this paper are introduced its geometric traits and separation mechanism. Experiments are carried out about the relationship between geometric parameters ＆ operating parameters and the separation efficiency of the compound hydrocyclone. Under experimental conditions, the appropriate structural parameters optimized are as follows： The rotating grid is of the straight board type, 3 straight vanes with a length of above 95 ram; the diameter of the overflow vent ranges 3-12 ram; the separation efficiency is better when the large conical angle of the static vortex body is about 20° and the small conical angle in the range of 1° -4° ： The separation effect is better under the following conditions： The rotary speed is 1,700-2,400 r/min; the disposal capacity is 5.5 m^3/h; the loss of working pressure is 0.05-0.25MPa; and the split ratio ranges 5%-15%. The experimental study provides a certain basis for the design andapplication of the compound hydrocyclone.展开更多
Asymmetric tree-like branched networks are explored by geometric algorithms. Based on the network, an analysis of the thermal conductivity is presented. The relationship between effective thermal conductivity and geom...Asymmetric tree-like branched networks are explored by geometric algorithms. Based on the network, an analysis of the thermal conductivity is presented. The relationship between effective thermal conductivity and geometric structures is obtained by using the thermal-electrical analogy technique. In all studied cases, a clear behaviour is observed, where angle （δ,θ） among parent branching extended lines, branches and parameter of the geometric structures have stronger effects on the effective thermal conductivity. When the angle δ is fixed, the optical diameter ratio β＋ is dependent on angle θ. Moreover, γand m are not related to β＊. The longer the branch is, the smaller the effective thermal conductivity will be. It is also found that when the angle θ〈δ2, the higher the iteration m is, the lower the thermal conductivity will be and it tends to zero, otherwise, it is bigger than zero. When the diameter ratio β1 〈 0.707 and angle δ is bigger, the optimal k of the perfect ratio increases with the increase of the angle δ; when β1 〉 0.707, the optimal k decreases. In addition, the effective thermal conductivity is always less than that of single channel material. The present results also show that the effective thermal conductivity of the asymmetric tree-like branched networks does not obey Murray＇s law.展开更多
The SF radical and its singly charged cation and anion, SF＋ and SF-, have been investigated on the MRCI/aug-cc- pVXZ （X = Q, 5, 6） levels of theory with Davidson correction. Both the core-valence correlation and th...The SF radical and its singly charged cation and anion, SF＋ and SF-, have been investigated on the MRCI/aug-cc- pVXZ （X = Q, 5, 6） levels of theory with Davidson correction. Both the core-valence correlation and the relativistic effect are considered. The extrapolating to the complete basis set （CBS） limit is adopted to remove the basis set truncation error. Geometrical parameters, potential energy curves （PECs）, vibrational energy levels, spectroscopic constants, ionization po- tentials, and electron affinities of the ground electronic state for all these species are obtained. The information with respect to molecular characteristics of the SFn （n = -1, 0, ＋ 1） systems derived in this work will help to extend our knowledge and to guide further experimental or theoretical researches.展开更多
基金supported by the Open Project of Key Laboratory of Aircraft Environment Control and Life Support,MIIT(No.KLAECLS-E-202001)。
文摘To improve the comfortability and safety of aircraft,the demand of rectangular submerged inlets(RSIs)with low resistance is proposed to increase the inlet flow rate of ram air. A theoretical model is built to numerically analyze the effects of geometric parameters on the inlet mass flow rate of RSIs. The geometric parameters in question here encompass the aspect ratio of 2—4,the ramp angle of 6°—7°,the characteristic parameter of the throat of 0.20 —0.30,the ramp length of 939—1 337 mm,and the cone angle of 0° —3°. Simulation results demonstrate that the mass flow rate(MFR)is positively correlated with the aspect ratio,ramp angle,ramp length,and cone angle,and negatively correlated with characteristic parameter of the throat. Within the range of the geometric parameters considered,the RSI with the aspect ratio of 3,the ramp angle of 6°,the characteristic parameter of the throat of 0.20,the ramp length of 1 337 mm,and the cone angle of 3° obtains the largest MFR value of about 2.251 kg/s.
基金Supported by the National Natural Science Foundation of China under Grant Nos.U22A20242 and 52301313.
文摘A novel semi-submersible platform is proposed for 5 MW wind turbines.This concept focuses on an integrated system formed by combining porous shells with a semi-submersible platform.A coupled aerodynamic–hydrodynamic–mooring analysis of the new system is performed.The motion responses of the novel platform system and the traditional platform are compared.The differences in hydrodynamic performance between the two platforms are also evaluated.The influence of the geometric parameters(porosity,diameter,and wall thickness)of porous shells on the motion response behavior of the new system is studied.Overall,the new semi-submersible platform exhibits superior stability in terms of pitch and heave degrees of freedom,demonstrating minimal effects on the motion response in the surge degree of freedom.
文摘A compound hydrocyclone is a new strategy for oil-water separation. It is based on the study of static and dynamic hydrocyclones. In this paper are introduced its geometric traits and separation mechanism. Experiments are carried out about the relationship between geometric parameters ＆ operating parameters and the separation efficiency of the compound hydrocyclone. Under experimental conditions, the appropriate structural parameters optimized are as follows： The rotating grid is of the straight board type, 3 straight vanes with a length of above 95 ram; the diameter of the overflow vent ranges 3-12 ram; the separation efficiency is better when the large conical angle of the static vortex body is about 20° and the small conical angle in the range of 1° -4° ： The separation effect is better under the following conditions： The rotary speed is 1,700-2,400 r/min; the disposal capacity is 5.5 m^3/h; the loss of working pressure is 0.05-0.25MPa; and the split ratio ranges 5%-15%. The experimental study provides a certain basis for the design andapplication of the compound hydrocyclone.
基金Project supported by the State Key Development Program for Basic Research of China (Grant No 2006CB708612)the National Natural Science Foundation of China (Grant No 10572130)the Natural Science Foundation of Zhejiang Province, China (Grant No Y607425)
文摘Asymmetric tree-like branched networks are explored by geometric algorithms. Based on the network, an analysis of the thermal conductivity is presented. The relationship between effective thermal conductivity and geometric structures is obtained by using the thermal-electrical analogy technique. In all studied cases, a clear behaviour is observed, where angle （δ,θ） among parent branching extended lines, branches and parameter of the geometric structures have stronger effects on the effective thermal conductivity. When the angle δ is fixed, the optical diameter ratio β＋ is dependent on angle θ. Moreover, γand m are not related to β＊. The longer the branch is, the smaller the effective thermal conductivity will be. It is also found that when the angle θ〈δ2, the higher the iteration m is, the lower the thermal conductivity will be and it tends to zero, otherwise, it is bigger than zero. When the diameter ratio β1 〈 0.707 and angle δ is bigger, the optimal k of the perfect ratio increases with the increase of the angle δ; when β1 〉 0.707, the optimal k decreases. In addition, the effective thermal conductivity is always less than that of single channel material. The present results also show that the effective thermal conductivity of the asymmetric tree-like branched networks does not obey Murray＇s law.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11304023 and 11447172)the Young and Middle-Aged Talent of Education Burea of Hubei Province,China(Grant No.Q20151307)the Yangtze Youth Talents Fund of Yangtze University,China(Grant No.2015cqr21)
文摘The SF radical and its singly charged cation and anion, SF＋ and SF-, have been investigated on the MRCI/aug-cc- pVXZ （X = Q, 5, 6） levels of theory with Davidson correction. Both the core-valence correlation and the relativistic effect are considered. The extrapolating to the complete basis set （CBS） limit is adopted to remove the basis set truncation error. Geometrical parameters, potential energy curves （PECs）, vibrational energy levels, spectroscopic constants, ionization po- tentials, and electron affinities of the ground electronic state for all these species are obtained. The information with respect to molecular characteristics of the SFn （n = -1, 0, ＋ 1） systems derived in this work will help to extend our knowledge and to guide further experimental or theoretical researches.
