Incident Wind Research Articles

Wind Effects on Re-Entrant Wing Faces of Plus Plan-Shaped Building

The wind flow patterns and pressure distribution around a plus-shaped building are significantly influenced by re-entrant corner dimensions and building height. The present study aims to find the wind effects and study the pressure distribution with different flow patterns. The building has a plan area of approximately 300 square meters and a height of 50 m, maintaining equal lengths for the re-entrant corners. The research study is performed using the ANSYS CFX academic version. The study employs diverse visualizations, featuring the pressure coefficient (CPe), vertical and specific surface streamlines, and pressure contours. Wind incidence angles for the study are varied from 0° to 90° at an interval of 15°. Building dimensions are scaled down as per the ASCE wind tunnel test manual, and the length scale is kept at 1:100 for CFD investigation. This approach yields crucial insights into the circulation of wind patterns and the distribution of pressure across a wide range of wind incidence angles. The influence of streamlines in the bottom portion of the building model is relatively minimal. In contrast to the upper portion, the bottom exhibits robust vortices, particularly for the wind angles varying from 0° to 30°. Positive pressure is observed on the windward face, and the leeward face and side face exhibit negative pressure. This study furnishes valuable insights into flow patterns and pressure distribution across a wide range of wind incidence angles from 0° to 90° at an interval of 15°. These findings contribute significantly to a thorough comprehension of the wind flow patterns and pressure distribution around the plus-shaped building model.

Wind loads on structural members of rack-supported warehouses

Rack-supported warehouses (RSWs) represent a modern typology of storage racks. In this system, cladding panel weight and corresponding applied loads, such as wind or snow load, are supported by storage racks, in addition to pallet load and seismic action. While this structural system allows for reducing the amount of structural steel, the uprights and beams, composing each rack, are directly exposed to the wind during the earliest erection phases. This load condition may govern the design of the uprights or that of temporary bracings. Wind load estimation requires the knowledge of the aerodynamic coefficients of each structural member section, for any angles of wind incidence. Unlike any common structural steelwork section, no data are available in the literature for RSW member sections. The current work represents a first step to cover this lack in the literature by reporting the results of an extensive wind tunnel campaign carried out on several portions of uprights and beams commonly designed and produced for RSWs. The results highlight the need for wind tunnel tests on RSW member sections when producers can no longer afford an overestimation of the wind load. In addition, conservative values of the aerodynamic coefficients are provided for preliminary wind load estimations or temporary bracings design. Empirical relationships for the aerodynamic coefficients, changing with equivalent side ratio, are also reported. Finally, design recommendations are provided by highlighting a critical structural configuration during the early erection phases of RSWs that govern the design of the uprights or temporary bracings. A worked example is then developed to clarify the application of the present results in the definition of wind loads.

Stability analysis of two-dimensional flat solar trackers using aerodynamic derivatives at different heights above ground

In this paper the aerodynamic stability of a flat-plate solar tracker under two-dimensional conditions is studied for different conditions of incident wind speed, U∞, nominal angle of attack, αn∈−40∘,40∘, and shaft height - chord ratio H/B=0.3,0.4,0.5,0.6,1and2. The stability is studied through the analysis of the aerodynamic derivatives A2∗ and A3∗ whose behaviours as a function of U∞ are presented for the H/B range studied. Two methods of obtaining the derivatives (one in the time domain and the other one in the frequency domain) are presented. A method for calculating the effective damping coefficient of the solar tracker, ξeff, as a function of the incident wind speed, U∞, is presented. This method can be used for any solar tracker structural characteristics (Jmech, Cmech and Kmech). With this method, the critical speed, Ucrit, can be determined by imposing the condition ξeff=0. The method was validated experimentally using the results of two different experimental set-ups.

CFD Study of Pressure Distribution on Recessed Faces of a Diamond C-Shaped Building

A building situated in the flow path of the wind is subjected to differential velocity and pressure distribution around the envelope. Wind effects are influenced by and vary for each individual shape of a tall building. Tall building structures are considered as cantilever structures with fixed ends at the ground. Wind velocity acting along the height of the building makes the velocity and pressure distribution more complex; as the height of the building structure increases, wind velocity increases. This study discusses the effect of the wind on an irregular cross-section shape. The present study was conducted numerically with a building model placed in a virtual wind tunnel using the ANSYS (CFX 2020 Academic Version) software tool. Wind effects are investigated on a building model situated in a terrain category-II defined in IS: 875 (Part 3): 2015; wind scale model of 1:100 and turbulence intensity are at 5% and power law index α is considered to be 0.143. The validation and verification of the study were made by comparing pressure coefficients on different faces of a rectangular model of similar floor area and height as that taken for a C-plan dia-mond-shaped model under similar boundary conditions, wind environment, and solver setting of numerical setups. The values of surface pressures generated on the recessed faces of the model and wind flow patterns within the recessed cavity were studied at wind incident angles 0°, 30°, 60°, 105°, 135°, and 180°. The critical suction on all the recessed faces was observed to be at a 105° angle of wind attack.

Airflow Dynamics and Aeolian Sand Transport Across a Beach‐Climbing Dune‐Clifftop Dune System

AbstractThis study presents an analysis of wind flow and sediment transport from the beach up a 50 m high, long (130 m), steep (mean slope 26°) climbing dune and across a 1.5 m high max, 85 m long and 17.5 m wide clifftop dune 30 km south of Dakhla in Morocco, NW Africa, during highly oblique incident wind conditions. Multiple 2D sonic and cup/vane anemometers and sand traps were utilized for measurements. Flow steering was significant on the upper climbing dune. Flow deceleration occurred near the dune toe, and topographic forcing of flow was considerable on the upper slopes of the climbing dune. Near‐surface flow steadiness (CVU1, CVU0.25) on the climbing dune straight slope segment was low and constant. The distance upslope over which the airflow reached a speed comparable to that on the beach increases as the incident wind speed increases. The greatest flow acceleration and speed‐up was observed at the cliff edge reaching 250% at 1 m height and 220% at 0.25 m height for the lowest incident wind speed class (4–5 m/s). The sand transport rate declined from the beach to the climbing dune toe and lower slope, but at the uppermost section of the climbing dune was 4 times higher than in the beach for the 7–8 m/s incident wind speed. Sand in aeolian transport was generally finer than surface sand, with the mean grain size increasing up the slope. A comparison of the sand transport data collected with sand transport models, and the effects of slope on Aeolian transport are also examined.

Assessment of summer outdoor thermal comfort in an urban neighborhood with high-rise buildings

The use of urban vegetation and ventilation corridors can be beneficial in terms of outdoor thermal comfort. High-rise buildings modify urban ventilation by redirecting incident wind flow, which can further complicate local thermal conditions. The present study investigates the interaction of building morphology and urban vegetation during heat wave conditions. A coupled multiscale approach is performed that allows for a detailed analysis of the local impact of vegetation and high-rise buildings in an urban neighborhood in Zurich, Switzerland. Existing configuration in the neighborhood with low-rise buildings of mostly uniform height is modified with high-rise buildings. Mesoscale meteorological simulations are employed to drive the flow in building-resolved computational fluid dynamics (CFD) simulations at microscale. The results show significantly lower air temperature around groups of trees and along main streets aligned with the predominant wind direction. However, there are also locations where air temperature increases due to the presence of trees, especially when there is limited exchange with the main ventilation corridor. Initial simulations with high-rise buildings show that they can have a large influence on air temperature in the immediate neighborhood.

Structural parameters of Wrench – C shape building using CFD

Wind flow pattern and generation of strong and large eddies is mainly responsible to the wind pressure and suction intensity in and around the tall building. If the shape of the structure is not vary common then the wind generated effects need to evaluate for the high rise structure this is because of the reason that the data for the regular plan cross sectional shape is available in the various international standards. This study investigating the wind effects on irregular cross sectional shape tall building using CFD tool ANSYS CFX. The current study evaluates the wind impacts for a boundary layer atmospheric wind flow from 0° to 180° at a 15° interval. The power law described in IS: 875 (Part 3): 2015 for terrain category II follows the wind profile. For a rectangular model, the values of the pressure coefficients are compared using the numerical simulation and the information supplied in IS 875. Results are given at numerous locations, including pressure coefficients around the building model’s periphery and force and moment coefficients for wind incidence angles ranging from 0° to 180° at 15° intervals.

Reliability-based Fire Protection of Structural Cables due to Deck Fires on Cable Supported Bridges

Cable supported bridges are typically part of community-critical infrastructure and therefore the consequences arising from extensive structural damage due to a fire and the subsequent operational discontinuity could be significant beyond the damage to the bridge itself and the cost of repairs. Bridge design standards generally do not provide guidance and hence fire resistance requirements are often informed by first principles assessments of the thermal and structural response of the structure to proposed fire scenarios. A deterministic assessment can provide a reasonable worst-case scenario but it does not allow bridge stakeholders to make informed decisions with regards to uncertainty and the low likelihood of fires occurring to identify the benefits of investments in structural fire protection. This is because the target reliability required for each bridge may be different depending on its characteristics, and the expected fire severity has a probabilistic nature. This research aims to fill this gap by undertaking a reliability-based analysis to assess the probability of structural failure by considering the probability of a fire of a given size occurring and the uncertainty in the incident location and wind. The methodology is demonstrated through the case study of an operational 450 m long cable supported bridge section and a fire scenario based on a liquid fuel tanker. Liquid tankers can result into two type of fire scenario: first, a fire being contained within the tanker; and secondly, a fire due to a pool on the deck. Both fire scenarios have been characterised and it was determined that the contained tanker scenario presents a more onerous design case owing to its more prolonged duration. A Monte Carlo analysis was undertaken for a total of 10,000 independent trials of the combination of the location of the fire and the wind direction. The frequency of the fire was also examined to establish the probability of structural failure of a cable. It was established that the inclusion of wind can sometimes reduce the estimated height at which cables may experience temperatures with the potential to cause cable failure. However, for a number of the cases, the estimated height can remain broadly similar (i.e. within a couple metres difference) to the worst-case calculated value. Based on this analysis, the influence of the required level of reliability as well the fire protection duration specification agreed with bridge stakeholders can be used to determine the height at which cable fire protection is necessary to reduce the probability of structural failure to a level acceptable to the stakeholders. This approach allows bridge designers and stakeholders to make informed decisions with regards to provision and extent of fire preventive/protective measures for cable supported bridges.

Advancing Our Understanding of Martian Proton Aurora Through a Coordinated Multi‐Model Comparison Campaign

AbstractProton aurora are the most commonly observed yet least studied type of aurora at Mars. In order to better understand the physics and driving processes of Martian proton aurora, we undertake a multi‐model comparison campaign. We compare results from four different proton/hydrogen precipitation models with unique abilities to represent Martian proton aurora: Jolitz model (3‐D Monte Carlo), Kallio model (3‐D Monte Carlo), Bisikalo/Shematovich et al. model (1‐D kinetic Monte Carlo), and Gronoff et al. model (1‐D kinetic). This campaign is divided into two steps: an inter‐model comparison and a data‐model comparison. The inter‐model comparison entails modeling five different representative cases using similar constraints in order to better understand the capabilities and limitations of each of the models. Through this step we find that the two primary variables affecting proton aurora are the incident solar wind particle flux and velocity. In the data‐model comparison, we assess the robustness of each model based on its ability to reproduce a proton aurora observation. All models are able to effectively simulate the general shape of the data. Variations in modeled intensity and peak altitude can be attributed to differences in model capabilities/solving techniques and input assumptions (e.g., cross sections, 3‐D vs. 1‐D solvers, and implementation of the relevant physics and processes). The good match between the observations and multiple models gives a measure of confidence that the appropriate physical processes and their associated parameters have been correctly identified and provides insight into the key physics that should be incorporated in future models.

The Effect of Wind Direction on the Cooling Capacity of Short Dry Natural Draft Cooling Towers Operating in Close Proximity

Abstract The layout of multiple natural draft dry cooling towers could have a significant influence on the performance of the cooling system in concentrated solar power (CSP) plants; however, this has never been quantified. Hence, this work used computational fluid dynamics (CFD) modeling to analyze the cooling capacity of two short natural draft dry cooling towers (NDDCTs) on a common site for a range of tower spacings, wind-speeds, and wind incidence angles. The results show that the cooling performance of the towers is a strong function of tower spacing and their orientation with respect to the wind direction. It was found that when the wind came at a 90-deg wind incidence angle (i.e., normal to a line drawn between the two towers), their cooling capacity was improved at tower spacings of less than 1.8 tower diameters (1.8D), though for the other tower spacings, there was no interaction between the towers. However, with the wind at 45 deg to the towers, the flow around the towers resulted in a decrease in their cooling capacity at tower spacings of 1.8D and 2.6D. Most interestingly, it was found that orienting the towers in line with the prevailing wind direction delivered improvements in the cooling capacity of up to 30%. This is due to the windward tower acting as a passive windbreak. Hence, as CSP plant capacity is increased, and additional cooling towers are required, these should be placed close to any existing tower and oriented along the line of the prevailing winds.

Energy losses in photovoltaic generators due to wind patterns

Previously, in small scale demonstrations, researchers have increased photovoltaic efficiency through cooling by enhancing heat transfer from panels to the air through wind speed. Here I show in the real-world operation of a larger scale photovoltaic generator that increases in wind speed can lead to small but notable energy losses, reflected in the mismatch losses directly derived from the operating voltage of each module. Temperature distribution was measured simultaneously with the operating voltages, alongside the local wind speed and direction. Temperature differences arose from the variable heat transfer throughout the panel, depending on the wind incidence. This affected the operating temperature of each module, consequently affecting their operating voltage and the overall mismatch losses with losses increasing by up to 0.28%. My results suggest that wind patterns cannot be neglected, considering long-term energy estimations and the lifespan of a photovoltaic power plant.

Shape optimization of a corner‐recessed square tall building to reduce mean wind pressure using a multi‐objective genetic algorithm

SummaryThe current study aims to determine how the corner recession affects tall buildings with square plans. A series of numerical simulations have been conducted to find the parametric models' wind pressure. Visualization tools, such as contour plots and streamlines, present the wind flow near the buildings. Numerical simulations are conducted using RANS k‐ℇ turbulence models considering a length scale of 1:300. Subsequently, a shape optimization study has been carried out to propose a suitable percentage of corner recession, which should minimize the wind pressure on different faces of the building. As design factors, the amount of corner recession (S) and the wind incidence angle (Ø) are taken, along with the mean pressure coefficients (Cp) on the various building faces. Due to the eight axes symmetry of the building configuration, the random sampling technique is used for the Design of Experiment while accounting for the 0°–45° wind angle of attack. The Response Surface Approximation (RSA) is used to construct surrogate models of the objective functions. The RSA models are validated with wind tunnel test results presented in previously published articles. The optimization study is carried out using the multi‐objective genetic algorithm technique.

Estimating Maximum Power from Wind Turbines with a Simple Newtonian Approach

Recent findings in action mechanics showing torques result from rates of variation in impulsive action motivated this more fundamental approach to estimate maximum power from wind turbines. Newton’s third law of equality of action and reaction provides a strictly causal mechanism of wind power from the deflection of wind momentum by twice its angle (θ) of incidence on rotor blades. The lateral reaction needed to conserve wind momentum provides the turning moment for the turbine rotors. This direct approach challenges the current continuum mechanism for generating power from flows of kinetic energy in wind passing through the areas swept by rotating blades. Action mechanics integrates the rates of impulsive wind action on turbine blades as torques (∫mrvdθ/dt ≡ mv2) exerted on rotor surfaces at decreasing radii. Windward torque (Tw) is estimated from rotor dimensions, the angle of wind incidence and radial action of wind impulses on the blade surfaces (also ∫mrvdθ/dt ≡ mv2). A leeward torque (Tb) for back reaction of turbine blades on air mimics drag exerted parallel to the plane of rotation of the blade. Net torque is then converted to potential power (Tw - Tb)Ω by the angular velocity (Ω) of the turbine rotors, a function of tip speed ratio to wind speed. New contributions from action mechanics for managing wind power include larger estimates of its possible magnitude by including vortical energy, much larger than the kinetic energy. Better predictions of limits to wind power can be made, by including control of optimal wind angle and blade length. An analysis of the equivalence of deflected air momentum on turbine blades or air foils for aircraft reveals that even the lifting action on air foils can be explained by the normal reaction to the momentum in an air stream, also deflected by an angle twice that (2θ) of incidence, validating application of action mechanics to airflight. A mechanism for release of vortical field energy from laminar flow of air in anticyclones is predicted in turbulent downstream wakes, possibly assisting achievement of maximum power output by wind farms. Significant heat release by downwind turbulence from vortical energy requires care for their location. Diligence demands that use of windfarms as major sources of renewable energy should minimize any environmental impacts, such as drying of landscapes.

EFFECTS OF ROOF SHAPES ON WIND PRESSURE DISTRIBUTION OF MULTI-SPAN LOW-RISE BUILDINGS

The present study demonstrates the numerical investigation to find out the effects of roof shapes on the wind pressure distribution of multi-span low-rise buildings. Most of the wind load standards of various nations are provided with wind load information of isolated low-rise buildings which in turn practically came out to be inapplicable during the designing of low-rise buildings with multi-spans. Also, most of the wind load studies are carried out using boundary layer wind tunnel (BWLT) which is sometimes not available, time taking process, and is expensive. Therefore, in the present research, numerical simulation has been done for the model of a low-rise building. For investigation, the Ansys CFX platform has been used with the k-ε turbulence model for different angles of wind incidence at an interval of 15°. The wind pressure distribution has been investigated for the model low-rise building with a rectangular plan having six spans of different roof forms i.e., cylindrical roof, mono-slope roof, hip roof, and dome roof. The outcomes of the present numerical investigations are presented in the contour plots of wind pressure and coefficients of wind-induced pressure on the different roof forms of low-rise buildings. The outcomes of the study will be so much beneficial to structural design engineers while considering the wind loads calculations on the different roof forms for low-rise buildings.

Impact of MTMD on response control of “V” shaped tall building under dynamic wind excitation

In the present study, the principal objective is to investigate the role of multiple tuned mass damper (MTMD) to reduce aerodynamic effect of wind force on “V” plan-shaped high-rise buildings with the various internal limb angle. Distinct cases have been made by considering the angle between the limbs is 90° which is gradually increased from 90° to 150° with 15° regular interval and decreased from 90° to 40° with 10° regular interval maintaining same plan area and limb width subjected from 0° to 180° wind incidence angle with 30° regular interval. Computational fluid dynamics (CFD) is adopted to determine the aerodynamic coefficients by numerical simulation. A polynomial expression has been proposed to compute force, moment, and torsional coefficient along X, Y, and Z direction from the entire result for avoiding rigorous calculation. Dynamic wind time history in along and crosswind is obtained using maximum force coefficient. The dynamic response analysis such as peak displacement, acceleration is obtained for selected models with MTMD and effectiveness of MTMD is computed. Finally, the influence of MTMD and internal angle variation on the wind-induced response of “V” plan-shaped buildings have been observed to determine suitability of internal angle variation based on the numerical result.

Isolating and Investigating Updrafts Induced by Wildland Fires Using an Airborne Doppler Lidar During FIREX‐AQ

AbstractUnderstanding the complex dynamical interactions that occur during the evolution of a wildland fire still remains a challenge within the research community. Processes such as entrainment, the incident wind field, the interaction between neighboring updrafts, among other processes, motivates the need for more intensive measurement campaigns to determine the mechanisms responsible for the processes observed as wildland fire updrafts evolve. A recent opportunity to examine processes associated with wildland fires was made possible with a Doppler lidar (DL) mounted on a Twin Otter aircraft to measure horizontal and vertical winds during the 2019 Fire Influence on Regional‐to‐Global Environments and Air Quality campaign. Using the data collected, a technique was developed to isolate updrafts over designated hotspots with the intention of statistically analyzing the updraft samples as well as assessing specific cases that underscore the complex dynamical interactions generated by wildland fire behavior. Strong evidence in support of statistically derived relationships between the updraft characteristics and downdraft extrema at the flanks of updrafts are shown using methods developed herein. In addition to the influence of entrainment/detrainment on the updraft structure are features such as updraft displacement and interacting updrafts that could only be resolved by a high along‐ and cross‐beam resolution DL. Lastly, it was found that a high degree of symmetry between profiles to the left and right of core updrafts was preserved for most of the cases, which validates some of the assumptions typically used in idealized updraft formulations.

Aerodynamic characteristics of a high-rise building in a steady thunderstorm outflow-like flow field

This paper investigates the aerodynamic characteristics of a high-rise building loaded by steady wind flows with different boundary layer profile shapes. The multiple-fan wind tunnel (MFWT) at Tamkang University was used to simulate a mean velocity field with a nose-shaped boundary layer profile, similar to that observed in thunderstorm outflows, and a standard boundary layer flow, both with 3–5% turbulence over the depth of the profile. A regular ‘open terrain’ boundary layer flow was also generated using spires and roughness blocks to enable comparison. Aerodynamic characteristics of the Commonwealth Aeronautical Advisory Research Council (CAARC) building loaded by each of these flow fields through a range of incidence angles were measured, analyzed, and compared. Results showed that pressures on the windward face of the building largely reflected the dynamic pressure in the incident wind field. Pressures on faces within the separated wake region were less easily explained. Incident mean velocity and turbulence profiles, as well as building orientation, were all found to influence measured wind loads and forcing spectra on these faces. Of particular interest was a significant reduction in cross-wind forcing observed in the simulated outflow-like winds, largely believed to occur because the lower elevation of strong winds in this profile limits the development of a separation vortex up the height of the building. It was also found that the estimated building response was almost universally lower in the outflow-like flow field when compared with the boundary layer cases.

Numerical Simulation of the Lunar Polar Environment: Implications for Rover Exploration Challenge

The lunar polar regions are key areas for future exploration due to the long-term continuous illumination and persistently shadowed regions that can cold trap abundant water and other volatiles. However, the complex terrain, dynamic lighting, and solar wind-induced electric-field environment present multiple challenges for polar investigation and sampling missions. China’s Chang’E-7 (CE-7) will explore the Moon’s south polar region in 2026. One of the scientific goals is to drill samples in a wide area with a rover for in situ analysis. This study analyzes the engineering constraints of the polar illumination condition, slopes, and electric field for landing and sampling-site selection. Then, we create a 3D model of CE-7’s lunar rover in three operating environments by employing the Spacecraft Plasma Interaction Software, with the rover sampling (i) on a flat surface, (ii) in a shadow, and (iii) near a meter-scale crater under different solar altitude angles. The results show that the rover can be charged to different potentials under the combined effects of solar wind incident angles and surrounding terrains. We find that a favorable traversing and/or sampling site of the rover for future polar exploration is in the upwind direction of a bulge (positively elevated terrains, such as the lander or boulders) or crater, which will cause a minimum charging effect on the rover. Our results have important implications for minimizing the risk of charging effects and guiding the lunar polar region exploration.

Experimental investigation of the aerodynamic performance of Flettner rotors for marine applications

Flettner rotors are becoming alternative wind-assisted propulsion systems for marine applications. This study experimentally investigated the aerodynamic performance of large-scale Flettner rotors with a diameter D = 350 mm, 0 = α ≤ 4.5, 3.5 = L/D ≤ 6.0, 1.0 ≤ De/D ≤ 2.0, and 9.33 × 104 ≤ Re ≤ 3.15 × 105, where α is the velocity ratio, L is the cylinder span, De is the diameter of the endplate, and Re is the Reynolds number based on D. The initial, increasing, decreasing, and stable areas were defined to describe the variation in the time-averaged lift-to-drag ratio K‾ with an increase in α. Both the aerodynamic performance of Flettner rotors and the range of the four areas were significantly influenced by L/D, De/D, and Re. Based on the measurement of the aerodynamic forces acting on the tested Flettner rotor under the influence of an interfering Flettner rotor with the same α, the effects of aerodynamic interaction for different wind incidence angles β and spacing ratios S/D were studied in detail. In addition, the driving and heeling force coefficients were presented for the combination of two Flettner rotors. Once the arrangement of the two Flettner rotors installed on the deck of a ship was known, both the driving and heeling forces provided by the combination of these rotors depended on α and the apparent wind angle.

A comprehensive performance evaluation methodology for sea-crossing cable-stayed bridges under wind and wave loads

This study proposes a probabilistic performance evaluation framework for sea-crossing cable-stayed bridges (SCBs) subjected to wind and wave excitations with the incorporation of wind speed and direction, bridge orientation, wind-wave correlation and parameter uncertainties. Both the bridge serviceability and safety are taken into account in the performance assessment. The fragility analysis of the SCB under wind and wave loads is conducted using the wind-wave correlation model constructed based on field data. The actual damage probability of a local SCB is computed by combining the fragilities of bridge under different wind incidence angles with the copula-based joint probability distribution (JPD) of wind speed and direction, which is developed using the wind field data recorded in Lianyungang city of China from 1971 to 2020. The results show that under the defined wind incidence angle of 0°, the exemplar SCB suffers the highest fragility. Moreover, with the data-based occurrence probability model of wind and wave hazards, the damage probabilities under all possible wind speeds and directions are computed; then the optimal and most unfavorable orientations of the SCB are obtained. This investigation provides a comprehensive and practical method for the performance evaluation and design optimization of SCBs under wind and wave loads with long-term recorded hazard data at the local site.