Seven adjustments of convergent-type Vortex Tube （VT） with different throttle angles were applied. The adjustments were made to analyze the influences of such angles on cold and hot temperature drops as well as flow...Seven adjustments of convergent-type Vortex Tube （VT） with different throttle angles were applied. The adjustments were made to analyze the influences of such angles on cold and hot temperature drops as well as flow structures inside the VTs. An experimental setup was designed, and tests were performed on different convergent VT configurations at injection pressures ranging from 0.45 to 0.65 MPa. The angles of the throttle valve were arranged between 30° to 90°, and the numbers of injection nozzles ranged between 2 and 6. Laboratory results indicated that the maximum hot and cold temperature drops ranged from 23.24 to 35 K and from 22.87 to 32.88 K, respectively, at four injection nozzles. Results also showed that temperature drop is a function of hot throttle valve angle with the maximum hot and cold temperature drops depending on the angle applied. We used graphs to demonstrate the changes in the cold and hot temperature drops with respect to hot throttle angle values. These values were interpreted and evaluated to determine the optimum angle, which was 60°. The CFD outputs agreed very well with the laboratory results. The proposed CFD results can help future researchers gain good insights into the complicated separation process taking place inside the VTs.展开更多
A numerical investigation of the three-dimensional conical spouted bed was conducted using CFD coupled with discrete element method to systematically analyze particle-gas flow patterns,bubble volume fluctuations,and f...A numerical investigation of the three-dimensional conical spouted bed was conducted using CFD coupled with discrete element method to systematically analyze particle-gas flow patterns,bubble volume fluctuations,and fountain characteristics.Moreover,the impact of conical angles on dynamic characteristics is demonstrated under varying gas inlet velocity and particle diameter.Firstly,the simulation result shows that increasing the conical angle is advantageous for enhancing both y-direction and angular velocities of particles,while the impact of this angle varies with inlet velocity and particle diameter.The great inlet velocity and particle diameter significantly enhance the voidage,while the larger conical angle promotes the uniform radial particle distribution.Besides,smaller conical angle and medium inlet velocity is prone to result in the higher frequency and amplitude for the fluctuations of particle height.Meanwhile,enlarging the conical angle results in a shift of the fountain frequency from high to low when the particle size is small.The conical angle plays a crucial role in determining bubble behavior under the condition of medium velocity and small diameter.Besides,the fine particle and small conical angle are prone to cause the noticeable main frequencies.展开更多
文摘Seven adjustments of convergent-type Vortex Tube （VT） with different throttle angles were applied. The adjustments were made to analyze the influences of such angles on cold and hot temperature drops as well as flow structures inside the VTs. An experimental setup was designed, and tests were performed on different convergent VT configurations at injection pressures ranging from 0.45 to 0.65 MPa. The angles of the throttle valve were arranged between 30° to 90°, and the numbers of injection nozzles ranged between 2 and 6. Laboratory results indicated that the maximum hot and cold temperature drops ranged from 23.24 to 35 K and from 22.87 to 32.88 K, respectively, at four injection nozzles. Results also showed that temperature drop is a function of hot throttle valve angle with the maximum hot and cold temperature drops depending on the angle applied. We used graphs to demonstrate the changes in the cold and hot temperature drops with respect to hot throttle angle values. These values were interpreted and evaluated to determine the optimum angle, which was 60°. The CFD outputs agreed very well with the laboratory results. The proposed CFD results can help future researchers gain good insights into the complicated separation process taking place inside the VTs.
文摘A numerical investigation of the three-dimensional conical spouted bed was conducted using CFD coupled with discrete element method to systematically analyze particle-gas flow patterns,bubble volume fluctuations,and fountain characteristics.Moreover,the impact of conical angles on dynamic characteristics is demonstrated under varying gas inlet velocity and particle diameter.Firstly,the simulation result shows that increasing the conical angle is advantageous for enhancing both y-direction and angular velocities of particles,while the impact of this angle varies with inlet velocity and particle diameter.The great inlet velocity and particle diameter significantly enhance the voidage,while the larger conical angle promotes the uniform radial particle distribution.Besides,smaller conical angle and medium inlet velocity is prone to result in the higher frequency and amplitude for the fluctuations of particle height.Meanwhile,enlarging the conical angle results in a shift of the fountain frequency from high to low when the particle size is small.The conical angle plays a crucial role in determining bubble behavior under the condition of medium velocity and small diameter.Besides,the fine particle and small conical angle are prone to cause the noticeable main frequencies.
