Wind-driven rain (WDR) is the primary source of building moisture, and it has a direct impact on the durability and thermal performance of building envelopes. To suppress the impact of WDR on ...buildings under climate change, this study analyzed three representative concentration pathways (RCP) scenarios (RCP2.6, RCP4.5, and RCP8.5) based on the climate data of Meteonorm and assesses China's forecasted WDR for the next 80 years. The WDR exposure maps and the WDR increase maps of China's three future emission scenarios in 2050, 2080, and 2100 were plotted, and the rate of increase of WDR was calculated. A total of ten representative cities in China were selected based on their WDR exposure. Using the ASHRAE 160-2021 standard, WDR patterns of 16 orientations of building facades in the ten selected cities in 2050, 2080, and 2100 under three future climate scenarios were obtained. The results show that China's overall WDR exposure will increase under the three future climate scenarios, with the increase under the RCP4.5 scenario being the largest. From a regional perspective, southeastern China is exposed to severe WDR in current scenarios and may also be exposed to the same in future scenarios; the absolute increase of WDR is also the largest. There are certain differences in WDR exposure and increase of WDR exposure in cities in different climate zones in China, and the increase in coastal areas is significantly greater than that in inland areas. Particularly, in Shanghai, the exposure of WDR evidently increases both in summer and winter.
•Wind-driven rain index under three RCP scenarios are projected.•Increase in wind-driven rain is more pronounced in coastal areas than inland.•Increase rate of wind-driven rain index under RCP 4.5 is the largest.•Wind-driven rain's seasonal change in summer and winter should be further studied.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Rainfall has significant impacts on the operations of wind turbines due to erosion of turbine blades and alterations in aerodynamic performance of wind turbines. However, little is understood in the ...influences of rainfall on wind turbine wakes. In this study, large-eddy simulation (LES) coupled with actuator-disk model with rotation (ADM-R) is used to investigate impacts of rainfall on wind turbine wakes. A double Euler method is employed in ADM-R to simulate the rainfall injection. The results of the model indicate that rainfall reduces wind speed in the sweep area and increases wind speed in the outer region of the top tip level by 2.1 %. Furthermore, rainfall reduces turbulence intensity in the near wake and outer wake region of the top tip (up to 2.0 %), with the influence extending up to 10 d (diameters of the wind turbine) in the downstream. These changes have a positive correlation with the rainfall intensity and an inverse correlation with the wind speed. The mean kinetic energy (MKE) and turbulent kinetic energy (TKE) budget analysis reveals that (1) the turbulent radial transport variation of MKE is the primary reason for the rainfall-induced wind speed change; (2) the change in shear production of TKE is responsible for the rainfall-induced turbulent intensity change; (3) the rainfall-induced Reynolds stress −u′w′‾ is the dominant factor of this dynamics.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The amount, duration, and intensity of wind-driven rain (WDR) are instrumental to the durability and sustainability of building components. Semi-empirical methods implemented in heat, air, and ...moisture (HAM) models have proved to be a practical and efficient approach to quantify WDR exposure of building components and to examine WDR's influence on hygrothermal responses of building envelopes. However, specific assumptions and simplifications in the implementations can cause discrepancies in WDR calculations and hygrothermal responses. While measured datasets or computational fluid dynamics (CFD) predictions are employed to validate WDR calculations in previous studies, few address the further influence on hygrothermal responses, particularly confronted with full-scale experimental datasets. This paper starts with a general formulation of semi-empirical methods for WDR calculation and elaborates the ASHRAE and ISO standards implemented in two representative HAM models, WUFI and DELPHIN. In the first phase of simulations, two full-scale experimental datasets at Leuven (Belgium) and Eindhoven (the Netherlands) are reproduced by the two models to compare predicted WDR loads. In the second phase, the predicted and measured WDR loads are imposed as boundary conditions of different scenarios of one benchmark case to further analyze the influence on the hygrothermal responses. The results indicate that both models roughly reproduce the semi-empirical methods. Because of disparity in algorithms and implementations and differences in weather and building conditions, the simulated WDR loads show similar trends with deviations to the measured datasets. The predicted hygrothermal responses show deviations to different extents, presumably due to disparity in WDR load predictions during certain periods.
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•ASHRAE and ISO standards are implemented into WUFI and DELPHIN with simplifications.•Full-scale measured WDR loads are confronted with simulated results from HAM models.•Deviations in incremental WDR amounts govern predicted hygrothermal responses.•Inter-model comparison and sensitivity analysis are necessary for model validation.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In nature, wind often occurs simultaneously with rainfall, causing nutrient loss in soil and water on slopes. However, the influence of different rainfall intensities combined with different wind ...directions on soil erosion and nutrient loss remains unclear. This study utilized wind‐driven rainfall laboratory flume experiments to analyse the influence of different wind directions (windward, leeward and crosswind) and rainfall intensities (30, 60 and 90 mm h−1) with constant wind speed (5 m s−1) on slope runoff, sediment yield and the associated losses of different forms of N (
NH4+,
NO3−) and P (
PO43−‐P). The response of soil erosion, N and P loss to rainfall changes with different wind directions. When the rainfall intensity was constant, runoff, sediment yield and sediment‐associated total nitrogen (TN) and total phosphorus (TP) losses on slopes showed a trend of leeward > crosswind > windless > windward, whereas runoff‐associated TN and TP losses showed a trend of windward > crosswind > windless > leeward. Runoff, sediment yield and sediment‐associated TN and TP losses on leeward slopes were 1.09–1.17, 1.25–1.44, 1.33–1.62, and 1.40–1.66 times than windless slopes. Moreover, with constant wind direction, the runoff, sediment yield and associated N and P losses increased significantly with increasing rainfall intensity. When the rainfall intensity increased from 30 to 60 and 90 mm h−1, the runoff, sediment yield and associated TN and TP losses increased 2.02–2.28, 3.65–5.35, 3.96–34.39 and 4.28–8.45 times, respectively. The effects of rainfall on soil erosion and nutrient loss were significantly greater than those of wind. The loss of different forms of N and P associated with runoff and sediment was consistent with that of TN and TP losses. However, with an increase in rainfall intensity, the growth rates of runoff, sediment yield and associated N and P losses exhibited a gradually weakening trend for all wind directions. An increase in rainfall intensity enhanced the vertical vector force of wind‐driven rainfall, which increasingly decreased the angle between the rain incidence and the normal line of the horizon; therefore, the direction of the rain erosion force gradually approached that of windless conditions.
Response of soil erosion and nutrient loss on different wind directions in laboratory flume experiments.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Prediction and risk assessment of hydrological extremes are great challenges. Following climate predictions, frequent and violent rainstorms will become a new hazard to several regions in the medium ...term. Particularly agricultural soils will be severely threatened due to the combined action of heavy rainfall and accompanying winds on bare soil surfaces. Based on the general underestimation of the effect of wind on water erosion, conventional soil erosion measurements and modeling approaches lack related information to adequately calculate its impact. The presented experimental-empirical approach shows the strong impact of wind on the erosive potential of rain. The tested soils had properties that characterize three environments 1. Silty loam of semi-arid Mediterranean dryfarming and fallow, 2. clayey loam of humid agricultural sites and 3. cohesionless sandy substrates as found at coasts, dune fields and drift-sand areas. Total erosion was found to increase by a factor of 1.3 to 7.1, depending on site characteristics. A complementary laboratory procedure was applied to quantify explicitly the effect of wind on raindrop erosion as well as the influence of substrate, surface structure and slope on particle displacement. These tests confirmed the impact of wind-driven rain on total erosion rates to be of great importance when compared to all other tested factors. To successfully adapt soil erosion models to near-future challenges of climate change induced rain storms, wind-driven rain should be included into the hazard management agenda.
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•Strong impact of wind-driven rain on soil erosion and runoff generation•Susceptibility of different environments to climate change associated storm impact•Improvement of environmental risk assessment by empirical evaluation
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Wind-driven rain (WDR) is the amount of rainfall that passes through a vertical plane due to its co-occurrence with wind, which can adversely impact the performance of building façades. Hygrothermal ...and durability analysis of façades require quantification of future WDR loads for a changing climate. This study evaluates projected changes to WDR loads across Canada for the end of century using regional climate model simulations for the Representative Concentration Pathway scenario 8.5. WDR loads are quantified in terms of omnidirectional and directional WDR amounts over periods of interest, which are relative indicators of WDR exposure and potential moisture content of absorbent surfaces, respectively. Furthermore, return levels of annual maximum WDR spell amounts, which are representative of the risk penetration through the façade, are also used to develop WDR risk category maps for Canada and specifically for 16 Canadian cities.
Future projections suggest increases in WDR loads for Arctic Canada, due to increases in both rainfall and wind magnitudes, while for other regions with increased loads, it is mostly due to increases in rainfall. Results suggest a shift in the timing of the highest monthly WDR loads from summer to fall, which is suggestive of higher WDR penetration through wall systems, given the relatively low evaporation rate in fall compared to summer even in a warmer climate. Furthermore, the developed WDR risk category maps show changes to critical façade orientations with elevated risk in future climate. This information is crucial in the development of detailed guidelines to ensure climate-resilient buildings.
•WDR loads projected to increase for many Canadian regions in future climate.•Shifts in WDR loads to cooler periods suggest higher damage risks.•Changes to most critical façade orientation projected for some locations.•Newly developed risk category maps suggest more regions at higher risk.•Research outcomes to inform development of new climate-resilient design guidelines.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In the history of human civilization, rammed earth has been used over thousand years to construct infrastructure, such as buildings, shelters, and defense structures. The structural integrity of ...rammed earth infrastructure can be affected by many factors over time. Abundant rainfall and typhoon can strike the World Heritage site of Fujian Tulou due to its unique geographic location in the southeast costal line of China. The effect of wind-driven rainfall on durability of rammed earth materials taken from three demolished Tulou sites with different construction history is studied. Laboratory element tests are conducted to identify that both the unconfined compressive strength and shear strength are inversely proportional to the water content. In drip tests, the maximum degree of erosion is obtained, when the rain direction falls within the range of 30–45°. In rain simulation tests, the peak erosion depth is measured for the case with a rain direction of 15–30°. Essentially, higher degree of erosion is resulted when the initial water content is higher, and lower degree of erosion is obtained when the clay content is higher.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Biocides used in building façades to prevent potential growth of algae, fungi and bacteria are of major concern regarding the quality of stormwater runoff. The aim of the study was to analyze the ...influence of the façade orientation on the biocide release under real weather conditions to gain information for the development of on-site treatment systems. Field tests with model houses containing two different plaster compositions were carried out over a period of 18 months. The results of the analyzed rain events demonstrate that façade orientation plays an important role in the leaching loads of biocides. Biocide loads in the runoff decreased corresponding to the wind direction. High cumulated active substance discharges of diuron (149 mg/m2), carbendazim (43.5 mg/m2), terbutryn (9.3 mg/m2) and octylisothiazolinone (OIT) (31.9 mg/m2) were found in the runoff of the façades facing the predominant weather orientation. Meanwhile, the highest concentrations of diuron (2.8 mg/L) and OIT (0.7 mg/L) were observed in the runoff from façades with smaller runoff volumes. The obtained results demonstrate that treatment facilities have to be installed at all building sides. The hydraulic and the substance load is highest at the weather side, which has a strong influence on the dimension and the lifetime of the treatment system.
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•Façade leaching was investigated under real conditions at all cardinal directions.•The weather side has a higher runoff load of biocides.•The results could influence the development of on-site treatment plants.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Wind-driven rain (WDR) has significantly unfavorable effects on the performance and durability of the enclosure systems of low-rise buildings. Therefore, a field measurement facility for the WDR on a ...gable-roofed low-rise building with overhang has been established and implemented in a typhoon-prone region of China. This paper presents and analyzes the field measurements of the WDR on the facades of the full-scale building during a typhoon in 2018. In addition, numerical simulations of the WDR on the instrumented building are performed using the Eulerian Multiphase model and validated based on the field measured WDR results. Then, a detailed parametric study of numerical simulation is carried out to examine the influences of roof overhang, wind speed, wind direction and horizontal rainfall intensity on the WDR amounts on the building facades. Next, the WDR on the low-rise building during a super typhoon are numerically reproduced and investigated. The measurement techniques and numerical simulation methodologies, analyzed results and conclusions presented in this paper would be useful to understand and evaluate the WDR on building facades so as to improve the serviceability of low-rise building envelopes.
•Establish measurement facility of wind driven rain (WDR) on a low-rise building.•Analyze measurements of WDR on the full-scale building during a typhoon.•Verify the numerical simulation results based on the field measurements.•Examine effects of key parameters on WDR by a detailed parametric study.•Further investigate WDR on the building under extreme weather condition.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
