Expand IntroductionIntroduction
Expand AdministrationAdministration
Expand User InterfaceUser Interface
Expand SolidWorks FundamentalsSolidWorks Fundamentals
Expand Moving from 2D to 3DMoving from 2D to 3D
Expand AssembliesAssemblies
Expand CircuitWorksCircuitWorks
Expand ConfigurationsConfigurations
Expand SolidWorks CostingSolidWorks Costing
Expand Design CheckerDesign Checker
Expand Design Studies in SolidWorksDesign Studies in SolidWorks
Expand Drawings and DetailingDrawings and Detailing
Expand DFMXpressDFMXpress
Expand DriveWorksXpressDriveWorksXpress
Expand FloXpressFloXpress
Expand Import and ExportImport and Export
Expand Large Scale DesignLarge Scale Design
Expand Model DisplayModel Display
Expand Mold DesignMold Design
Expand Motion StudiesMotion Studies
Expand Parts and FeaturesParts and Features
Expand RoutingRouting
Expand Sheet MetalSheet Metal
Collapse SimulationSimulation
Welcome to SolidWorks Simulation Online Help
Access to Help
Legal Notices
Collapse Analysis BackgroundAnalysis Background
SolidWorks Simulation Reference
Expand Linear Static AnalysisLinear Static Analysis
Expand Frequency AnalysisFrequency Analysis
Expand Dynamic AnalysisDynamic Analysis
Expand Linearized Buckling AnalysisLinearized Buckling Analysis
Collapse Thermal AnalysisThermal Analysis
Thermal Analysis
Collapse Mechanisms of Heat TransferMechanisms of Heat Transfer
Expand ConductionConduction
Expand ConvectionConvection
Collapse RadiationRadiation
Basic Radiation Definitions
Stefan-Boltzmann Law
Radiation Emission from Real Surfaces
Radiation Exchange Between Surfaces
Radiation from Shell Surfaces
Radiation View Factors
Performing Thermal Analysis
Thermal Contact Resistance
Types of Heat Transfer Analysis
Output of Thermal Analysis
Heat Power/Energy PropertyManager
Expand Nonlinear Static AnalysisNonlinear Static Analysis
Expand Drop Test AnalysisDrop Test Analysis
Expand Fatigue AnalysisFatigue Analysis
Pressure Vessel Overview
Expand Beams and TrussesBeams and Trusses
Expand 2D Simplification2D Simplification
Expand Simulation FundamentalsSimulation Fundamentals
Expand Simulation OptionsSimulation Options
Expand Simulation StudiesSimulation Studies
Expand Design StudiesDesign Studies
Expand 2D Simplification Study2D Simplification Study
Expand Composite ShellsComposite Shells
Expand Loads and RestraintsLoads and Restraints
Expand MeshingMeshing
Expand Material PropertiesMaterial Properties
Expand ParametersParameters
Expand Analysis LibraryAnalysis Library
Expand Viewing ResultsViewing Results
Expand Study ReportsStudy Reports
Expand Checking Stress ResultsChecking Stress Results
Expand SimulationXpressSimulationXpress
Expand SketchingSketching
Expand Sustainability ProductsSustainability Products
Expand SolidWorks UtilitiesSolidWorks Utilities
Expand TolerancingTolerancing
Expand ToolboxToolbox
Expand WeldmentsWeldments
Expand Workgroup PDMWorkgroup PDM
Expand TroubleshootingTroubleshooting
Expand GlossaryGlossary
Hide Table of Contents

Radiation View Factors

View factors, also known as shape or configuration factors, play a direct role in heat transfer due to radiation. The view factor Fij between two small areas Ai and Aj is defined as the fraction of the radiation leaving area Ai that is intercepted by area Aj . In other words, Fij represents how well Ai sees Aj . The view factor Fij depends on the orientation of the small areas Ai and Aj and the distance between them.

For the two infinitesimal surfaces dA i and dA j , the view factor dF ij is given by:

where q i and q j are the angles between the unit normals to the areas and the line R ij connecting the two areas. If the two areas are finite, then the view factor is given by:

From the above equation, the following reciprocity relation always holds:

While many heat transfer books provide view factors for simple-shaped areas, calculating view factors for real life problems requires major effort even for fast computers. When requested to calculate view factors for the radiation between face A and face B, the software thinks of each face as composed of small areas (surfaces) defined by element faces. It then calculates a view factor for each element face relative to every other element face in the set. View factors between element faces on the same geometrical face are included in these calculations.

A concave face with a reasonably fine mesh can radiate to itself. Planar and convex faces do not radiate to themselves. Such effects are automatically considered.


The radiation between two element faces can be blocked by a third element face. In that case, the view factor becomes 0. The software automatically considers blocking among all specified faces as illustrated in the figure. For proper blocking considerations, you must select faces participating in the radiation. In the example below, faces 3 and 4 partially block the radiation between faces 1 and 2. Incorrect results are obtained if you select faces 1, 2, and 3 only.


Provide feedback on this topic

SOLIDWORKS welcomes your feedback concerning the presentation, accuracy, and thoroughness of the documentation. Use the form below to send your comments and suggestions about this topic directly to our documentation team. The documentation team cannot answer technical support questions. Click here for information about technical support.

* Required

Subject:   Feedback on Help Topics
Page:   Radiation View Factors
*   I acknowledge I have read and I hereby accept the privacy policy under which my Personal Data will be used by Dassault Systèmes

Print Topic

Select the scope of content to print:


We have detected you are using a browser version older than Internet Explorer 7. For optimized display, we suggest upgrading your browser to Internet Explorer 7 or newer.

 Never show this message again

Web Help Content Version: SOLIDWORKS 2012 SP05

To disable Web help from within SOLIDWORKS and use local help instead, click Help > Use SOLIDWORKS Web Help.

To report problems encountered with the Web help interface and search, contact your local support representative. To provide feedback on individual help topics, use the “Feedback on this topic” link on the individual topic page.