Techno Press
You logged in as Techno Press

Wind and Structures
  Volume 38, Number 4, April 2024 (Special Issue) pages 261-275
DOI: https://doi.org/10.12989/was.2024.38.4.261
 


A compensation method for the scaling effects in the simulation of a downburst-generated wind-wave field
Xu Haiwei, Zheng Tong, Chen Yong, Lou Wenjuan and Shen Guohui

 
Abstract
    Before performing an experimental study on the downburst-generated wave, it is necessary to examine the scale effects and corresponding corrections or compensations. Analysis of similarity is conducted to conclude the non-dimensional force ratios that account for the dynamic similarity in the interaction of downburst with wave between the prototype and the scale model, along with the corresponding scale factors. The fractional volume of fluid (VOF) method in association with the impinging jet model is employed to explore the characteristics of the downburst-generated wave numerically, and the validity of the proposed scaling method is verified. The study shows that the location of the maximum radial wind velocity in a downburstwave field is a little higher than that identified in a downburst over the land, which might be attributed to the presence of the wave which changes the roughness of the underlying surface of the downburst. The impinging airflow would generate a concavity in the free surface of the water around the stagnation point of the downburst, with a diameter of about two times the jet diameter (Djet). The maximum wave height appears at the location of 1.5Djet from the stagnation point. Reynolds number has an insignificant influence on the scale effects, in accordance with the numerical investigation of the 30 scale models with the Reynolds number varying from 3.85 x 104 to 7.30 x 109 . The ratio of the inertial force of air to the gravitational force of water, which is denoted by G, is found to be the most significant factor that would affect the interaction of downburst with wave. For the correction or compensation of the scale effects, fitting curves for the measures of the downburst-wave field (e.g., wind profile, significant wave height), along with the corresponding equations, are presented as a function of the parameter G.
 
Key Words
    downburst-generated wave; similarity; fractional volume of fluid method; scale effects; numerical simulation
 
Address
Xu Haiwei:College of Civil Engineering and Architecture, Zhejiang University, Hangzhou 310058, China

Zheng Tong:College of Civil Engineering and Architecture, Zhejiang University, Hangzhou 310058, China

Chen Yong:College of Civil Engineering and Architecture, Zhejiang University, Hangzhou 310058, China

Lou Wenjuan:College of Civil Engineering and Architecture, Zhejiang University, Hangzhou 310058, China

Shen Guohui:College of Civil Engineering and Architecture, Zhejiang University, Hangzhou 310058, China
 

Techno-Press: Publishers of international journals and conference proceedings.       Copyright © 2024 Techno Press
P.O. Box 33, Yuseong, Daejeon 305-600 Korea, Tel: +82-42-828-7996, Fax : +82-42-828-7997, Email: admin@techno-press.com