A combination of the lattice Boltzmann method and lagrangian Runge-Kutta procedure is used to stu... more A combination of the lattice Boltzmann method and lagrangian Runge-Kutta procedure is used to study dispersion and removal of nano-particles in a concentric annulus. The effect of aspect ratio, Rayleigh number and particles diameter are examined on particles removal and their dispersion characteristics. Simulations are performed for the Rayleigh number ranges from 103 to 105 and aspect ratio of 2, 3 and 4. Higher aspect ratios have led to weaker recirculation strength. The finest particles move on stochastic path due to the effect of Brownian motion. The Brownian motion has a greater effect on the removal of nano--particles with respect to thermophoresis.
In the present study, the lattice Boltzmann method is implemented to investigate the effect of su... more In the present study, the lattice Boltzmann method is implemented to investigate the effect of suspension of nanoparticles on mixed convection in a square cavity with inlet and outlet ports and hot obstacle in the center of the cavity. The effect of outlet port location is examined on heat transfer rate then the effect of nanoparticles is inspected for volume fraction of nanoparticles in the range of 0 to 0.03 at the different position of outlet port. The study was carried out for different Richardson numbers ranging from 0.1 to 10. Grashof number is assumed to be constant (104) so that the Richardson number changes with Reynolds number. The isothermal boundary condition is assumed for obstacle walls and the cavity walls are adiabatic. The result is presented by isotherms, streamlines, and local and average Nusselt numbers. The maximum heat transfer rate occurs when the outlet port is located at P2 for Ri=0.1 and P1 for Ri=1, Ri=10, respectively. Results show that by adding the nanoparticles to base fluid and increasing the volume concentration of nanoparticles the heat transfer rate is enhanced at different Richardson numbers and outlet port positions. But this phenomenon is not observed at Ri=10 when the outlet port is located at P1.
In this study, interparticle potential model (Shan and Chen) of lattice Boltzmann method is emplo... more In this study, interparticle potential model (Shan and Chen) of lattice Boltzmann method is employed to simulate the dripping and detachment of immiscible droplet under gravity force. In order to validate the simulations, free deformation of initialized square drop, coalescence of two adjacent drops and the Laplace law of two dimensional drops have been investigated. Dynamic behaviors of droplet, i.e. droplet detachment from ceiling of channel and droplet detachment from left solid wall of channel with different conditions of wall wetting properties are õinvestigated. Simulation results are presented for different Eotvos numbers (3≤Eo≤48) at the small Ohnesorge number (Oh = 0.07), as well. The results show that the droplet will not detach from wettable wall in low Eotvos numbers (Eo ≤ 6), but in hydrophobic walls, the droplet detaches from the wall in total range of examined Eotvos number.
Dispersion and deposition of microparticles are investigated numerically in a channel in the pres... more Dispersion and deposition of microparticles are investigated numerically in a channel in the presence of a square obstacle and inlet flow pulsation. Lattice Boltzmann method (LBM) is used to simulate the flow field and modified Euler method is employed to calculate particles trajectories with the assumption of one-way coupling. The forces of drag, gravity, Saffman lift and Brownian motion are included in the particles equation of motion. The effects of pulsation amplitude (AMP), Strouhal number and particles Stokes number (Stk) are rigorously studied on particles dispersion and deposition efficiency. Flow vortex shedding and particles dispersion patterns together with the averaged fluid–particle relative velocity and deposition efficiency plots are all discussed thoroughly. The results show that increment of pulsation amplitude enforces the vortices to form closer to the obstacle until their shape deteriorates as Strouhal number ratio (SNR) rises. The average recirculation length shrinks to its minimum at each studied Amp when SNR escalates to 2. Various behaviors are categorized for dispersion pattern of particles when Stokes number changes from 0.001 to 4. Deposition efficiency is indirectly related to Amp for Stk ≤ 2 while for higher Stokes numbers (2 < Stk ≤ 4) they show direct relationship. Deposition pattern becomes rather independent of SNR at Amp = 0.1. The grid independency test was performed for the LBM analysis, and simulation code was successfully verified against credible benchmarks.
Dispersion and removal of micro aerosol particles are investigat ed numerically in a horizontal c... more Dispersion and removal of micro aerosol particles are investigat ed numerically in a horizontal concentric annulus by Lattice Boltzmann Method and Lagrangian Runge–Kutta procedure with the assumption of one-way coupling. Drag, buoyancy, gravity, shear lift, Brownian motion and thermophoretic are forces that are included in particle equation of motion. All simulations were performed at Rayleigh number of 104 and particles specific density of 1000. The effect of aspect ratio and particles diameter were determined on particles behavior such as removal and dispersion. Results show that recirculation power increases by decreasing of cylinders gap. Particles move in a thinner quasi-equilibrium region by increasing of their diameter and decreasing of cylinders gap. Brownian motion is dominant removal mechanism in particle with diameter of 1 micrometer.
A combination of the lattice Boltzmann method and lagrangian Runge-Kutta procedure is used to stu... more A combination of the lattice Boltzmann method and lagrangian Runge-Kutta procedure is used to study dispersion and removal of nano-particles in a concentric annulus. The effect of aspect ratio, Rayleigh number and particles diameter are examined on particles removal and their dispersion characteristics. Simulations are performed for the Rayleigh number ranges from 103 to 105 and aspect ratio of 2, 3 and 4. Higher aspect ratios have led to weaker recirculation strength. The finest particles move on stochastic path due to the effect of Brownian motion. The Brownian motion has a greater effect on the removal of nano--particles with respect to thermophoresis.
In the present study, the lattice Boltzmann method is implemented to investigate the effect of su... more In the present study, the lattice Boltzmann method is implemented to investigate the effect of suspension of nanoparticles on mixed convection in a square cavity with inlet and outlet ports and hot obstacle in the center of the cavity. The effect of outlet port location is examined on heat transfer rate then the effect of nanoparticles is inspected for volume fraction of nanoparticles in the range of 0 to 0.03 at the different position of outlet port. The study was carried out for different Richardson numbers ranging from 0.1 to 10. Grashof number is assumed to be constant (104) so that the Richardson number changes with Reynolds number. The isothermal boundary condition is assumed for obstacle walls and the cavity walls are adiabatic. The result is presented by isotherms, streamlines, and local and average Nusselt numbers. The maximum heat transfer rate occurs when the outlet port is located at P2 for Ri=0.1 and P1 for Ri=1, Ri=10, respectively. Results show that by adding the nanoparticles to base fluid and increasing the volume concentration of nanoparticles the heat transfer rate is enhanced at different Richardson numbers and outlet port positions. But this phenomenon is not observed at Ri=10 when the outlet port is located at P1.
In this study, interparticle potential model (Shan and Chen) of lattice Boltzmann method is emplo... more In this study, interparticle potential model (Shan and Chen) of lattice Boltzmann method is employed to simulate the dripping and detachment of immiscible droplet under gravity force. In order to validate the simulations, free deformation of initialized square drop, coalescence of two adjacent drops and the Laplace law of two dimensional drops have been investigated. Dynamic behaviors of droplet, i.e. droplet detachment from ceiling of channel and droplet detachment from left solid wall of channel with different conditions of wall wetting properties are õinvestigated. Simulation results are presented for different Eotvos numbers (3≤Eo≤48) at the small Ohnesorge number (Oh = 0.07), as well. The results show that the droplet will not detach from wettable wall in low Eotvos numbers (Eo ≤ 6), but in hydrophobic walls, the droplet detaches from the wall in total range of examined Eotvos number.
Dispersion and deposition of microparticles are investigated numerically in a channel in the pres... more Dispersion and deposition of microparticles are investigated numerically in a channel in the presence of a square obstacle and inlet flow pulsation. Lattice Boltzmann method (LBM) is used to simulate the flow field and modified Euler method is employed to calculate particles trajectories with the assumption of one-way coupling. The forces of drag, gravity, Saffman lift and Brownian motion are included in the particles equation of motion. The effects of pulsation amplitude (AMP), Strouhal number and particles Stokes number (Stk) are rigorously studied on particles dispersion and deposition efficiency. Flow vortex shedding and particles dispersion patterns together with the averaged fluid–particle relative velocity and deposition efficiency plots are all discussed thoroughly. The results show that increment of pulsation amplitude enforces the vortices to form closer to the obstacle until their shape deteriorates as Strouhal number ratio (SNR) rises. The average recirculation length shrinks to its minimum at each studied Amp when SNR escalates to 2. Various behaviors are categorized for dispersion pattern of particles when Stokes number changes from 0.001 to 4. Deposition efficiency is indirectly related to Amp for Stk ≤ 2 while for higher Stokes numbers (2 < Stk ≤ 4) they show direct relationship. Deposition pattern becomes rather independent of SNR at Amp = 0.1. The grid independency test was performed for the LBM analysis, and simulation code was successfully verified against credible benchmarks.
Dispersion and removal of micro aerosol particles are investigat ed numerically in a horizontal c... more Dispersion and removal of micro aerosol particles are investigat ed numerically in a horizontal concentric annulus by Lattice Boltzmann Method and Lagrangian Runge–Kutta procedure with the assumption of one-way coupling. Drag, buoyancy, gravity, shear lift, Brownian motion and thermophoretic are forces that are included in particle equation of motion. All simulations were performed at Rayleigh number of 104 and particles specific density of 1000. The effect of aspect ratio and particles diameter were determined on particles behavior such as removal and dispersion. Results show that recirculation power increases by decreasing of cylinders gap. Particles move in a thinner quasi-equilibrium region by increasing of their diameter and decreasing of cylinders gap. Brownian motion is dominant removal mechanism in particle with diameter of 1 micrometer.
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Papers by hamid hasanzade
of aspect ratio, Rayleigh number and particles diameter are examined on particles removal and their dispersion characteristics. Simulations are performed for the Rayleigh number ranges from 103 to 105 and aspect ratio of 2, 3 and 4. Higher aspect ratios have led to weaker recirculation strength. The finest particles move on stochastic path due to the effect of Brownian motion. The Brownian motion has a greater effect on the removal of nano--particles with respect to thermophoresis.
nanoparticles on mixed convection in a square cavity with inlet and outlet ports and hot obstacle in the center of the cavity. The effect of outlet port location is examined on heat transfer rate then the effect of nanoparticles is inspected for volume fraction of nanoparticles in the range of 0 to 0.03 at the different position of outlet port. The study was carried out for different Richardson numbers ranging from 0.1 to 10. Grashof
number is assumed to be constant (104) so that the Richardson number changes with Reynolds number. The isothermal boundary condition is assumed for obstacle walls and the cavity walls are adiabatic. The result is presented by isotherms, streamlines, and local and average Nusselt numbers. The maximum heat transfer rate occurs when the outlet port is located at P2 for Ri=0.1 and P1 for Ri=1, Ri=10, respectively. Results show that by adding the nanoparticles to base fluid and increasing the volume concentration of nanoparticles the heat transfer rate is enhanced at different Richardson numbers and outlet port positions. But this phenomenon is not observed at Ri=10 when the outlet port is located at P1.
number (Oh = 0.07), as well. The results show that the droplet will not detach from wettable wall in low Eotvos numbers (Eo ≤ 6), but in hydrophobic walls, the droplet detaches from the wall in total range of examined Eotvos number.
used to simulate the flow field and modified Euler method is employed to calculate particles trajectories with the assumption of one-way coupling. The forces of drag, gravity,
Saffman lift and Brownian motion are included in the particles equation of motion. The effects of pulsation amplitude (AMP), Strouhal number and particles Stokes number (Stk) are rigorously studied on particles dispersion and deposition efficiency. Flow vortex shedding and particles dispersion patterns together with the averaged fluid–particle relative velocity and deposition efficiency plots are all discussed thoroughly. The results show that increment of pulsation amplitude enforces the vortices to form closer to the obstacle until their shape deteriorates as Strouhal number ratio (SNR) rises. The average recirculation length shrinks to its minimum at each studied Amp when SNR escalates to 2. Various behaviors are categorized for dispersion pattern of particles when Stokes number changes from 0.001 to 4. Deposition efficiency is indirectly related to Amp for Stk ≤ 2 while for higher Stokes numbers (2 < Stk ≤ 4) they show direct relationship. Deposition pattern becomes rather independent of SNR at Amp = 0.1. The grid independency test was performed for the LBM analysis, and simulation code was successfully verified against credible benchmarks.
of aspect ratio, Rayleigh number and particles diameter are examined on particles removal and their dispersion characteristics. Simulations are performed for the Rayleigh number ranges from 103 to 105 and aspect ratio of 2, 3 and 4. Higher aspect ratios have led to weaker recirculation strength. The finest particles move on stochastic path due to the effect of Brownian motion. The Brownian motion has a greater effect on the removal of nano--particles with respect to thermophoresis.
nanoparticles on mixed convection in a square cavity with inlet and outlet ports and hot obstacle in the center of the cavity. The effect of outlet port location is examined on heat transfer rate then the effect of nanoparticles is inspected for volume fraction of nanoparticles in the range of 0 to 0.03 at the different position of outlet port. The study was carried out for different Richardson numbers ranging from 0.1 to 10. Grashof
number is assumed to be constant (104) so that the Richardson number changes with Reynolds number. The isothermal boundary condition is assumed for obstacle walls and the cavity walls are adiabatic. The result is presented by isotherms, streamlines, and local and average Nusselt numbers. The maximum heat transfer rate occurs when the outlet port is located at P2 for Ri=0.1 and P1 for Ri=1, Ri=10, respectively. Results show that by adding the nanoparticles to base fluid and increasing the volume concentration of nanoparticles the heat transfer rate is enhanced at different Richardson numbers and outlet port positions. But this phenomenon is not observed at Ri=10 when the outlet port is located at P1.
number (Oh = 0.07), as well. The results show that the droplet will not detach from wettable wall in low Eotvos numbers (Eo ≤ 6), but in hydrophobic walls, the droplet detaches from the wall in total range of examined Eotvos number.
used to simulate the flow field and modified Euler method is employed to calculate particles trajectories with the assumption of one-way coupling. The forces of drag, gravity,
Saffman lift and Brownian motion are included in the particles equation of motion. The effects of pulsation amplitude (AMP), Strouhal number and particles Stokes number (Stk) are rigorously studied on particles dispersion and deposition efficiency. Flow vortex shedding and particles dispersion patterns together with the averaged fluid–particle relative velocity and deposition efficiency plots are all discussed thoroughly. The results show that increment of pulsation amplitude enforces the vortices to form closer to the obstacle until their shape deteriorates as Strouhal number ratio (SNR) rises. The average recirculation length shrinks to its minimum at each studied Amp when SNR escalates to 2. Various behaviors are categorized for dispersion pattern of particles when Stokes number changes from 0.001 to 4. Deposition efficiency is indirectly related to Amp for Stk ≤ 2 while for higher Stokes numbers (2 < Stk ≤ 4) they show direct relationship. Deposition pattern becomes rather independent of SNR at Amp = 0.1. The grid independency test was performed for the LBM analysis, and simulation code was successfully verified against credible benchmarks.