scholarly journals HEAT TRANSFER TO VERTICAL GAS-SOLID SUSPENSION FLOWS

1978 ◽  
Vol 11 (2) ◽  
pp. 89-95 ◽  
Author(s):  
SHIGERU MATSUMOTO ◽  
SATOSHI OHNISHI ◽  
SIRO MAEDA
Keyword(s):  
Heat Transfer ◽  
Suspension Flows ◽  
Solid Suspension

Heat transfer and shear-induced migration in dense non-Brownian suspension flows: modelling and simulation

2018 ◽  
Vol 840 ◽  
pp. 432-454 ◽  
Author(s):  
T. Dbouk
Keyword(s):  
Heat Transfer ◽  
Thermal Diffusivity ◽  
Shear Rate ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Laminar Flows ◽  
Modelling And Simulation ◽  
Particle Migration ◽  
Concentrated Suspension ◽  
Suspension Flows

Modelling and simulation are developed, generalized and validated for both heat transfer and shear-induced particle migration in dense non-colloidal laminar suspension flows. Past theory and measurements for the effective thermal conductivity in porous materials at zero shear rate are coupled to more recent effective thermal diffusivity measurements of sheared suspensions. The suspension effective heat transfer affected by the local shear rate ($\dot{\unicode[STIX]{x1D6FE}}$), the phenomenon of shear-induced particle migration (SIM), the buoyancy effects ($\unicode[STIX]{x0394}\unicode[STIX]{x1D70C}$) and the thermal Péclet number ($Pe_{d_{p}}=\dot{\unicode[STIX]{x1D6FE}}d_{p}^{2}/\unicode[STIX]{x1D6FC}_{f}$, where $d_{p}$ is the diameter of rigid particles and $\unicode[STIX]{x1D6FC}_{f}$ is the fluid phase thermal diffusivity) at the particle scale are all considered in the present constitutive three-dimensional modelling. Moreover, the influence of the temperature, the shear rate and the particle volume fraction ($\unicode[STIX]{x1D719}$) on the suspension effective viscosity ($\unicode[STIX]{x1D702}_{S}$), the suspension effective thermal properties and the fluid density ($\unicode[STIX]{x1D70C}_{f}$) are taken also into account. The present contribution represents an emerging field of heat transfer applications of complex fluid flows and is very beneficial for many future applications where concentrated suspension laminar flows with conjugate heat transfer may be present (e.g. for designing more innovative and compact heat exchangers).

Heat Transfer to Horizontal Gas-Solid Suspension Flows

1970 ◽  
Vol 92 (1) ◽  
pp. 77-82 ◽  
Author(s):  
C. A. Depew ◽  
E. R. Cramer
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Solid Loading ◽  
Airflow Rate ◽  
Nusselt Numbers ◽  
Glass Spheres ◽  
Significant Difference ◽  
Solid Suspension ◽  
Bottom Side ◽  
Wall Interaction

Heat transfer and pressure-drop characteristics of a gas-solid suspension flow in a horizontal circular tube were investigated using glass spheres of two sizes, 30 and 200 micron. The airflow rate was held constant at three different values in a 0.71-in-ID tube such that Reynolds numbers of 10,000, 15,000, and 30,000 were produced. Solid loading ratios on a mass basis were as large as 7. The purpose of the investigation was to observe the effect of stratification on the heat transfer characteristics of the system. The pressure-drop results indicate that the solids were suspended in all cases, but the heat transfer data slum significant difference between the temperature of the tube wall at the top and bottom with the small particles. Nusselt numbers were as much as 2-1/2 times larger on the bottom side than on the top side. No such effect was produced with the large particles. The pressure-drop data indicate significant wall interaction for the large size, but not for the small size.

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