Woo et al. (2025) Application of a Combined Synthetic-Perturbation Method for Turbulent Inflow in Time-Varying Urban LES

⚠️ Warning: This summary was generated from the abstract only, as the full text was not available.

Identification

• Journal: Atmosphere
• Year: 2025
• Date: 2025-12-05
• Authors: J. H. Woo, Sang‐Hyun Lee
• DOI: 10.3390/atmos16121380

Research Groups

[Information not provided in the text.]

Short Summary

This study proposes and evaluates a combined digital-filter-based synthetic turbulence generator (STG) and cell perturbation method (CPM) as an inflow turbulence strategy for large-eddy simulations (LES) of urban boundary layers, demonstrating its ability to improve turbulence realism and vertical mixing while reducing computational cost for time-varying conditions.

Objective

• To investigate and propose an effective inflow turbulence strategy for large-eddy simulations (LES) of urban boundary layers under time-varying atmospheric conditions, specifically focusing on reducing turbulence adjustment distance and improving vertical mixing.

Study Configuration

• Spatial Scale: Urban domain (Seoul), neighborhood-scale, limited domain sizes.
• Temporal Scale: 24-hour simulations, capturing diurnal transitions in stability and wind direction.

Methodology and Data

• Models used: PALM model, Digital-filter-based Synthetic Turbulence Generator (STG), Cell Perturbation Method (CPM).
• Data sources: Real urban domain (Seoul) geometry and time-varying atmospheric conditions (specific source not detailed).

Main Results

• The combined CPM + STG strategy effectively mitigates abrupt structural transitions and sustains turbulence kinetic energy (TKE) more consistently compared to STG alone.
• CPM + STG requires lower computational cost than traditional extended-fetch configurations.
• Under unstable daytime conditions, CPM + STG enhanced vertical mixing and maintained local boundary-layer height closer to background values.
• During nighttime, building-induced shear dominated performance, making the specific inflow strategy less impactful.

Contributions

• Introduction and validation of a novel combined CPM + STG approach for robust inflow turbulence generation in urban large-eddy simulations (LES).
• Demonstration of a method that balances physical realism and computational efficiency for time-varying urban boundary layer simulations within limited domain sizes.
• Addresses the critical challenge of turbulence adjustment distance and accurate vertical mixing in urban LES.

Funding

[Information not provided in the text.]

Citation

@article{Woo2025Application,
  author = {Woo, J. H. and Lee, Sang‐Hyun},
  title = {Application of a Combined Synthetic-Perturbation Method for Turbulent Inflow in Time-Varying Urban LES},
  journal = {Atmosphere},
  year = {2025},
  doi = {10.3390/atmos16121380},
  url = {https://doi.org/10.3390/atmos16121380}
}