Methodology

Scientific foundation and technical approach to pedestrian wind comfort analysis

Computational Fluid Dynamics Framework

Governing Equations

Our simulations solve the Reynolds-Averaged Navier-Stokes (RANS) equations for incompressible flow, capturing the complex three-dimensional wind patterns around urban structures. The fundamental conservation equations include:

Continuity Equation:
∂ρ/∂t + ∇·(ρU) = 0
Momentum Equation:
∂(ρU)/∂t + ∇·(ρUU) = -∇p + ∇·τ + ρg

These equations are discretized using finite volume methods with high-order spatial schemes to ensure numerical accuracy and stability across complex urban geometries.

Turbulence Modeling

Accurate turbulence representation is critical for wind comfort prediction. We employ multiple modeling approaches depending on project requirements:

k-ε Realizable Model

Standard approach for most urban applications, providing robust convergence and validated results for building aerodynamics

SST k-ω Model

Enhanced near-wall treatment for complex geometries with significant flow separation and recirculation zones

Large Eddy Simulation

High-fidelity unsteady analysis for critical applications requiring detailed turbulence structure resolution

Atmospheric Boundary Layer Modeling

Wind Profile Implementation

Accurate representation of atmospheric conditions is essential for realistic wind comfort predictions. We implement site-specific wind profiles based on local meteorological data and terrain characteristics.

Power Law Profile:
U(z) = U_ref × (z/z_ref)^α
Logarithmic Profile:
U(z) = (u*/κ) × ln(z/z₀)

Terrain Classification

Site conditions are classified according to international standards, ensuring appropriate roughness parameters and atmospheric stability conditions.

Open Water/Flat Terrainα = 0.10
Suburban/Small Townsα = 0.20
Urban Centersα = 0.30

Wind Comfort Assessment Standards

Our analysis applies multiple internationally recognized comfort criteria, ensuring comprehensive assessment suitable for different activities and regulatory requirements across global markets.

Lawson Criteria (UK/Ireland)

Widely adopted standard correlating wind speeds with pedestrian activities and comfort levels, based on extensive field studies and observations.

Sitting (Long exposure)
< 4 m/s
Sitting (Short exposure)
< 6 m/s
Standing/Walking
< 8 m/s
Business Walking
< 10 m/s
Safety Threshold
15 m/s
Davenport Criteria (Canada)

Comprehensive framework developed for Canadian conditions, incorporating seasonal variations and specific activity classifications for urban planning.

Sitting
< 3.6 m/s
Standing
< 5.3 m/s
Strolling
< 7.6 m/s
Fast Walking
< 9.0 m/s
Safety Threshold
20 m/s
NEN 8100 (Netherlands)

Dutch national standard emphasizing pedestrian safety with specific provisions for cycling comfort and outdoor dining areas

Melbourne Criteria (Australia)

Climate-specific thresholds accounting for local wind patterns and seasonal variations in temperate coastal environments

Custom Criteria

Project-specific standards developed for unique climatic conditions or specialized applications requiring tailored assessment

Validation & Quality Assurance

Best Practice Guidelines

Our methodology adheres to established best practices from leading research institutions and professional organizations, ensuring reliable and defensible results.

COST Action 732 Guidelines
European framework for CFD quality and reporting standards
AIJ-CFD Guidelines (Japan)
Architectural Institute of Japan computational standards
ASCE Manual of Practice
American Society of Civil Engineers wind engineering guidelines

Verification Procedures

Multi-stage verification ensures simulation accuracy and reliability through systematic validation against experimental data and analytical solutions.

Mesh Independence

Grid refinement studies to ensure solution convergence and spatial accuracy requirements

Wind Tunnel Correlation

Validation against experimental data for similar building configurations and flow conditions

Sensitivity Analysis

Assessment of key parameter influences on final comfort predictions and uncertainty quantification

Implementation on windy.so

Our proven methodology deployed through cloud-based simulation platform

Automated Workflows

Pre-configured simulation templates implementing all methodology components, from mesh generation to comfort assessment, ensuring consistent application of best practices across all analyses.

Quality Controls

Built-in validation checks and convergence monitoring provide automatic quality assurance, with detailed diagnostics and recommendations for optimal simulation setup and execution.

Experience Our Methodology

Apply our scientifically validated approach to your wind comfort analysis projects