Simulation of Wind-Driven Rain Associated with Tropical Storms and Hurricanes using the 12-fan Wall of Wind

Publication date: Available online 12 March 2014
Source:Building and Environment
Author(s): Thomas Baheru , Arindam Gan Chowdhury , Girma Bitsuamlak , Forrest J. Masters , Ali Tokay
Wind-driven rain (WDR) is among the important environmental variables that affect the performance and durability of building enclosure systems. Although the need to investigate multi-level effects of WDR on building structures has increased through time, the available methods of investigation have been generally limited to field study and application of computational fluid dynamics. This paper investigates the parameters of tropical storm and hurricane-level WDR and presents a methodology of experimental simulation of WDR that may complement the two other investigation methods. Tropical cyclone WDR data acquired through National Aeronautics and Space Administrations’ Tropical Rainfall Measuring Mission ground validation program were used to study the characteristics of tropical storm and hurricane-level WDR and derive the values of target parameters, which were later used in the experimental simulation process. Procedure for determination of target WDR rate, simulation of raindrop size distribution and its integral parameters, and selection of type and number of nozzles are discussed in detail. Similarity requirements and important scaling considerations of WDR simulation were addressed. The procedure was used to simulate WDR using the 12-fan Wall of Wind facility at Florida International University. The experimental simulation results, presented herein, demonstrated satisfactory representation of target rainfall intensity and raindrop size distribution in the test setup. The WDR simulation methodology presented herein may be used for simulation of WDR in testing facilities to evaluate water intrusion in buildings during tropical cyclones, develop solutions to promote functional longevity of building envelope, and enhance current simplified test protocols given in international standards.