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Cylinder Domain - [source code]

Define a cylindrical simulation domain for Eddy3D. One cylindrical mesh serves all wind directions; the cylinder side faces switch between inlet and outlet per direction. The auto radius targets the 3% frontal-blockage limit of ASCE/SEI CWE Prestandard AC 6-8b, which the case component verifies. Model surrounding buildings within ~240 m of the study area (ASCE 49 proximity guidance) before trusting results near the context edge. Method: Kastner & Dogan (2020), Journal of Building Performance Simulation 13(1):59-68, doi:10.1080/19401493.2019.1692906; Kastner & Dogan (2018), eSim 2018 (IBPSA-Canada), Montréal, https://publications.ibpsa.org/conference/paper/?id=esim2018_1-2-A-4.

Input

Name Nickname Description Type
Core Cell Size Cell Cell size of the inner core blocks in meters. Default: 25. Number
Inner Core Size Inner Half-size of the square inner core in meters. -1 = auto from the building footprint. Number
Outer Radius Radius Outer radius of the cylindrical domain in meters. -1 = auto from the building height. Number
Height Height of the cylindrical domain in meters. -1 = auto from the building height. Number
Radial Multiplier RadMult Cell growth factor from the core toward the perimeter. Default: 2. Number
Core Divisions Divs Cells per core block (and per perimeter segment, tangentially). Refines the core without changing the block layout that Core Cell Size sets; the preview core grid densifies to match. Default: 1. Integer
Refinement Box Extension Refine Padding of the refinement box around the geometry (m). -1 = auto: 27.5% of the building footprint. Number
Radial Grading Grade Far-field cell coarsening across the perimeter ring (outer cell size / inner cell size). 1 = uniform; >1 keeps fine cells at the buildings but grows the outer cells. The default 7 coarsens the far field aggressively (far fewer cells downwind); lower it (1-3) for a gentler, more uniform ring. Default: 7. Number
Core Roundness Round Rounds the O-grid inner core from a square (0) toward a circle (1). Higher values even out the radial gap to the outer boundary, cutting the corner non-orthogonality of the square core. 0 keeps the classic square core. 0.65 is the checkMesh-sweep optimum (lowest max non-orthogonality across mesh resolutions; skewness stays well within limits). Default: 0.65. Number
Vertical Grading GradeZ Vertical cell expansion ratio (top cell size / bottom cell size). 1 = uniform; >1 keeps fine cells near the ground and coarsens aloft (typical for an ABL). A checkMesh sweep showed non-orthogonality/skewness are unaffected by this; the only cost is background aspect ratio. The default 35 strongly refines the near-ground layer; ease it down if convergence struggles. Default: 35. Number

Output

Name Nickname Description Type
Domain Parameters Domain Cylindrical domain parameters (-1 entries mean auto-sized from the building geometry); plug into the wind case Domain input. Generic Data