

June 5, 2023 at 7:05 amFAQParticipant
Section 8.5.3.2 of the CFX Modeling Guide, entitled “Particle Shape Factors”, explains the significance of the Cross Sectional and Surface Area Factors. The Guide mentions that CFX assumes all particles to be spherical by default, and continues this assumption while calculating a particle’s diameter from dividing its mass by its density. The Cross Sectional Area Factor may be included to modify the assumed spherical crosssectional area if the particles are actually nonspherical. This factor is multiplied by the calculated crosssectional area when assuming spherical particles, and affects the calculated drag force. To elaborate, let a cuboid particle’s dimensions be length (L) x width (W) x depth (D), where L>W>D. Then, let the following definitions be: •Crosssectional area, A = W*D •Volume, V = L*W*D •Equivalent spherical radius, Rv = (3/4*V/pi)^(1/3) •Cross Sectional Area Factor, CSAF = A/(pi*Rv^2) CSAF is then multiplied by the crosssectional area of the spherical particle equivalent of the cuboid particle. The Surface Area Factor (SAF) is analogous to the CSAF in that it adjusts the assumed spherical particle shape to enable nonspherical particles. However, this factor is defined as the ratio of the surface area of the nonspherical particle to the surface area of the spherical particle with the equivalent diameter (nonspherical divided by spherical). The SAF affects mass and heat transfer correlations and thus must be figured out based on the surface geometry of the nonspherical particle compared to the surface of a spherical particle of equivalent mass.

Introducing Ansys Electronics Desktop on Ansys Cloud
The Watch & Learn video article provides an overview of cloud computing from Electronics Desktop and details the product licenses and subscriptions to ANSYS Cloud Service that are...
How to Create a Reflector for a Center HighMounted Stop Lamp (CHMSL)
This video article demonstrates how to create a reflector for a center highmounted stop lamp. Optical Part design in Ansys SPEOS enables the design and validation of multiple...
Introducing the GEKO Turbulence Model in Ansys Fluent
The GEKO (GEneralized KOmega) turbulence model offers a flexible, robust, generalpurpose approach to RANS turbulence modeling. Introducing 2 videos: Part 1 provides background information on the model and a...
Postprocessing on Ansys EnSight
This video demonstrates exporting data from Fluent in EnSight Case Gold format, and it reviews the basic postprocessing capabilities of EnSight.
 Solver message during DPM calculation: “number of stepsize underflows during particle integration step is x”. What does it mean and how to get rid of it?
 ANSYS Fluent: Efficient Modeling of Spray Breakup using VOFtoDPM Transition
 ANSYS Fluent: Describing Cavitation in a Centrifugal Pump
 Simulation of Exhaust Gas Recirculation (EGR) Cooler with CFD
 Mixing Tank Modeling in ANSYS Fluent
 ANSYS Fluent: Lifeboat Launch – Overset & Dynamic Meshes with the Volume of Fluid Model
 Hydrodynamics and Wave Impact Analysis
 Optimizing Solid Distribution in Continuous StirredTank Reactor
 ANSYS Fluent: Simulating Multiphase Mixing within a Sparging Tank – Part 1
 ANSYS Fluent: Simulating Multiphase Mixing within a Sparging Tank – Part 2
© 2023 Copyright ANSYS, Inc. All rights reserved.