Beaufort Wind Scale Research Articles

INFLUENCE OF DIFFERENT WIND ANGLES ON PEDESTRIAN WIND COMFORT IN 3D SPACE

Abstract. Wind can impact pedestrian comfort. This comfort can be observed by integrating a 3D city model into the study area. However, little research has been done on the influence of different wind angles on pedestrian wind comfort and rarely on implementing 3D city models in the wind environment. Therefore, this study aims to fill the gap in using 3D city models to examine the effect of wind flow angles on pedestrian wind comfort. The Computational Fluid Dynamics (CFD) wind simulation environment presented in this study was constructed through the applied steady Reynolds-Average Navier-Stokes (RANS) with K-epsilon (k-ε) turbulence model. It is integrated with the standalone building model with a roof overhang structure represented in LoD2.3 of the CityGML standard. Three wind angles have been introduced to allow for variation in the analysis of pedestrian wind comfort: 0°, 15°, and 30° wind angles. Through the observation of multiple locations, which are directed beneath the roof overhang structure, the highest wind velocity is recorded in 0° wind angles compared to 15° and 30° wind angles. Thus, from these recorded values, pedestrian wind comfort is based on the Beaufort wind scale (BWS). The computed average recorded values show that 3.24 m/s corresponds to a wind angle of 0°, 2.761 m/s for 15°, and 2.415 m/s for 30°, which shows that all these values fall in BWS Scale 2. Thus, these areas experience a light breeze. However, the lowest value from a 30-degree environment presents the most reposeful surrounding.

Stochastic modelling of wind speed over northern states in Nigeria

This paper presents a stochastic modeling of wind speed over sixteen (16) Northern states in Nigeria using thirty-seven years (1984-2020) wind speed real time data. A Markov Chain Model was developed for the monthly wind speed state across study locations. In order to obtain the Markov chain transitional probabilities, the wind speed data was categories into various states using the Beaufort wind scale. It was observed that only the first four description of wind speed state A, B, C and D exist in the study locations. Uniform random states were also formed by generating uniform random number. The comparison of monthly simulated and actual wind speed state clearly shows that the model simulated over six months correctly across study locations except Niger. Given a current wind speed state conditions, the stochastic models available in this paper can be adapted to generate future wind speed state condition. The understanding of wind speed state helps in wind turbine design and selection of wind farm sites for wind energy generation.

An evaluation of childhood carbon monoxide intoxications in a rural area using the Beaufort wind scale.

Climatic changes are known to affect CO intoxications. The purpose of this study was to examine childhood CO intoxications with the Beaufort wind scale (BWS) classification of wind speeds. The demographic data (age and sex) and information concerning the hour, day, and month of presentation to the emergency department for cases diagnosed with CO intoxication over a 7-year period between 2015 and 2021 in the pediatric emergency department of a tertiary training and research hospital in a rural area were examined. Wind speeds (m/s) measured on the days of presentation to the emergency department were recorded. The wind category on the BWS on the day of intoxication was then determined. Four hundred twenty-two patients, with a mean age of 95.12 ± 59.4 (1-215) months, 218 (51.7%) girls and 204 (48.3%) boys were diagnosed with CO intoxication over the 7-year study period. A comparison of wind speeds on the days of presentation to hospital revealed a significantly higher wind speed in 2020 than in the other years (p<0.001). A comparison of the groups in terms of the BWS revealed a significant difference between the years of presentation to hospital (p:0.001). This is the first study to investigate CO intoxications in the pediatric emergency department with the BWS. A significant association was observed between wind speed based on the BWS and childhood CO intoxications. Further studies evaluating wind in the rural setting and CO intoxications are now needed for protection against such intoxications.

Research on rainbow probabilistic forecast model based on meteorological conditions in ZhaoSu region

AbstractAn analysis of artificial rainbow observations in ZhaoSu region from 2017 to 2019 shows that rainbows mainly occur between 16:00 and 22:00 (LST) from April to September. The analysis based on the meteorological observation in the same period shows that precipitation, temperature, wind force and cloud variety contribute to rainbow formation. Approximately 90% of rainbows appear one hour after rainfall, and 100% of rainbows occur when the Beaufort wind scale is less than level 8 following Beaufort wind scale (less than 20.9 m/s), the temperature is greater than 8°C, and the cloud amount is greater than 40%, respectively. A rainbow probabilistic forecast model is constructed based on five meteorological factors. The forecast ability of the model is independently assessed by comparing rainbow forecasts and its observation in 2020. The Brier score is 0.20, indicating that the objective model is effective for rainbow forecasts.

Effect of Indoor Condition with Cross Ventilation on Deposition of Airborne Droplets Emitted from Human Cough

Prediction of airborne transmission in different environmental condition remains as the research challenge in the field. This has motivated the present study to obtain the direct impact of flow field to the physical nature of transmission. ANSYS Fluent 2022 R1 software is utilised in this research to numerically investigate and visualize flow pattern in a closed environment with cross ventilation and its effect to the emitted droplets deposition. The effect of different indoor parameters towards airborne transmission are investigated, which include wind velocity, air relative humidity (RH), and exposure time after emission. Simulation result revealed increasing wind velocity according to Beaufort wind scale of 1.0 to 3.9 m/s, increases transmission rate due to enhanced convection effect. Surrounding air with higher RH leads to a larger mean diameter of particles due to hygroscopic growth effect, while evaporation effect dominates in lower air RH, leading to particle shrinkage. In a light wind breeze, droplet mass of 5.15 mg deposited on receiver body within 0.5 s of transmission when RH is 40%, while only 3.29 mg droplets reached receiver in RH of 99.5%. Droplet particles settle on the floor within 1.50 s revealed 0.66 mg deposited mass in higher RH, while 0.26 mg of droplets deposited in lower RH. Deposition at transmitter body is possible due to recirculation effect of incoming wind generated between transmitter and receiver, leading to 3.7 times higher deposited mass in lower RH as compared to in higher RH. This research highlights application of Euler-Lagrange model to represent the trajectory of cough droplets influenced by indoor condition with horizontal wind, in the effort to strengthen safety and health judgement in the event of a pandemic.

An Analysis of the Impact of Building Wind by Field Observation in Haeundae LCT Area, South Korea: Typhoon Omais in 2021

In the Haeundae area of Busan, South Korea, damage has continued to occur recently from building wind from caused by dense skyscrapers. Five wind observation stations were installed near LCT residential towers in Haeundae to analyze the effect of building winds during typhoon Omais. The impact of building wind was analyzed through relative and absolute evaluations. At an intersection located southeast of LCT (L-2), the strongest wind speed was measured during the monitoring. The maximum average wind speed for one minute was observed to be 38.93 m/s, which is about three times stronger than at an ocean observation buoy (12.7 m/s) at the same time. It is expected that 3 to 4 times stronger wind can be induced under certain conditions compared to the surrounding areas due to the building wind effect. In a Beaufort wind scale analysis, the wind speed at an ocean observatory was mostly distributed at Beaufort number 4, and the maximum was 8. At L-2, more than 50% of the wind speed exceeded Beaufort number 4, and numbers up to 12 were observed. However, since actual measurement has a limitation in analyzing the entire range, cross-validation with computational fluid dynamics simulation data is required to understand the characteristics of building winds.

A Review on the Building Wind Impact through On-site Monitoring in Haeundae Marine City: 2021 12th Typhoon OMAIS Case Study

Overcrowding of high-rise buildings in urban zones change the airflow pattern in the surrounding areas. This causes building wind, which adversely affects the wind environment. Building wind can generate more serious social damage under extreme weather conditions such as typhoons. In this study, to analyze the wind speed and wind speed ratio quantitatively, we installed five anemometers in Haeundae, where high-rise buildings are dense, and conducted on-site monitoring in the event of typhoon OMAIS to determine the characteristics of wind over skyscraper towers surround the other buildings. At point M-2, where the strongest wind speed was measured, the maximum average wind speed in 1 min was observed to be 28.99 m/s, which was 1.7 times stronger than that at the ocean observatory, of 17.0 m/s, at the same time. Furthermore, when the wind speed at the ocean observatory was 8.2 m/s, a strong wind speed of 24 m/s was blowing at point M-2, and the wind speed ratio compared to that at the ocean observatory was 2.92. It is judged that winds 2–3 times stronger than those at the surrounding areas can be induced under certain conditions due to the building wind effect. To verify the degree of wind speed, we introduced the Beaufort wind scale. The Beaufort numbers of wind speed data for the ocean observatory were mostly distributed from 2 to 6, and the maximum value was 8; however, for the observation point, values from 9 to 11 were observed. Through this study, it was possible to determine the characteristics of the wind environment in the area around high-rise buildings due to the building wind effect.

Mechanistic Drifting Forecast Model for A Small Semi-Submersible Drifter Under Tide–Wind–Wave Conditions

Understanding the drifting motion of a small semi-submersible drifter is of vital importance regarding monitoring surface currents and the floating pollutants in coastal regions. This work addresses this issue by establishing a mechanistic drifting forecast model based on kinetic analysis. Taking tide–wind–wave into consideration, the forecast model is validated against in situ drifting experiment in the Radial Sand Ridges. Model results show good performance with respect to the measured drifting features, characterized by migrating back and forth twice a day with daily downwind displacements. Trajectory models are used to evaluate the influence of the individual hydrodynamic forcing. The tidal current is the fundamental dynamic condition in the Radial Sand Ridges and has the greatest impact on the drifting distance. However, it loses its leading position in the field of the daily displacement of the used drifter. The simulations reveal that different hydrodynamic forces dominate the daily displacement of the used drifter at different wind scales. The wave-induced mass transport has the greatest influence on the daily displacement at Beaufort wind scale 5–6; while wind drag contributes mostly at wind scale 2–4.

Positive Pressure Ventilation for fighting wind-driven high-rise fires: Simulation-based analysis and optimization

In high-rise buildings wind can greatly impact fires, creating extremely dangerous and life-threatening environments for both the firefighters and the building's occupants. Positive pressure ventilation (PPV) is found to be a successful tactic, not only to mitigate wind driven fires in high-rises, but also to significantly improve firefighters’ safety. The efficacy of PPV is strongly influenced by various parameters, mainly structural layouts, wind conditions, and fan deployment configurations. To optimize the application of PPV in high-rise fires, this paper investigates the impact of wind speed (0–10m/s; 0–5 Beaufort wind scale) and relevant operational parameters on temperatures and smoke conditions using computational fluid dynamics model - the Fire Dynamics Simulator (FDS 5.0). The temperature results demonstrate that the effectiveness of PPV decreases with increasing wind speed necessitating the use of wind control devices (WCDs) in conjunction with deployment of PPV fans to mitigate the flow of heat and reduce the temperatures at primary vantage points (stairwell and public hallway). This tactic ultimately provides a safer environment for firefighters.

MODELLING THE EFFECT OF WIND FORCES ON LANDSLIDE OCCURRENCE IN BUDUDA DISTRICT, UGANDA

The hilly area of Bududa District, in Eastern Uganda has suffered heavily from landslide occurrence, making the local populace unsafe. Although the area is well covered by vegetation, a catastrophic landslide occurred on the 26th June, 2012 and killed more than 18 people and wiped out the nearby community. The fallen trees due wind effect prior to the landslide coupled with intense rainfall are believed to trigger that landslide. Therefore, the effect of commonly known causative factor of rainfall and an uncommon landslide causal factor of wind forces on landslide occurrence were investigated in this study. The geometry of the modelled slope consists of 111 m height, 480 m length, and an inclination of 21°. Finite element seepage software, Seep/W and limit equilibrium software, Slope/W were used for modelling the landslide occurrence using five (5) slope models with and without additional shear strength in form of tree root cohesion. Each of the slope models was subjected to four failure criteria (FC). The first two failure criteria (FC1 and FC2) are assigned for group of tree along the slope (FC1) and a single tree at the middle (FC2) of the modelled slope. The other two failure criteria (FC3 and FC4) are assigned for the modelled slope with rainfall infiltration alone and rainfall plus several tree weights, respectively. The wind speed during which the landslide occurred was depicted using Beaufort wind scale 11 and was applied to the appropriate models. The results obtained show that with eucalyptus trees of Diameters at Breast Heights (DBH) of 25 cm, a minimum factor of safety (FOS) of 1.012 and 1.273 were recorded for FC2 in Slope model 1 and slope model 4 with and without increased cohesion, respectively. This shows an increase in the FOS of 23.81%. However, when the DBH was increased to a maximum of 60 cm (i.e. in slope model 3), the safety of the modelled slope diminishes and the FOS reduces to 0.601 for FC2 on the 25th day, without cohesion, just some hours before the fateful day of the 26th June 2012. This FOS remained below 1.0 (0.800 to 0.601) for FC2 with roots cohesion, although a gain in the FOS of 33.11% was realized. Hence, it can be concluded that the uncommon natural causative factors of wind have a great influence on landslide occurrence in the hilly areas of Bududa district

Occurrence and species diversity of delphinids off-Lagos shore, Nigeria

Little has been documented about delphinid communities in the Nigerian coastal waters. This paper gives baseline information about the delphinid community sighted off-shore Lagos, Nigeria. A dedicated survey of the living resources of Nigerian coastal waters (6°08’N and 2°42’W to 6° 13’N and 3° 27’W ) took place from the Nigeria/Benin boarder along Badagry area to the western part of Ondo State between 17th march and 6th June 2009 and included systematic visual searching of marine mammals. A total effective effort of 264 hours was logged. The boat moved along designated transect lines at a cruising speed of 9.2 km/h. Sighting rate for delphinids was obtained by processing visual data obtained at Beaufort wind scale of 2.5 to 4 nautical miles in visibility, using Distance 2.2 software. Species were identified through Photo-identification method. Fifteen (15) schools of 746 individual’s sightings were made. Four (4) schools of 25 individuals representing 3% of total sightings were classified as “Unidentified”, while 11 schools of 721 individuals (97%) were identified and classified into five (5) species. The pantropical spotted dolphin ( Stenella attenuate ) with two (2) schools of 150 individuals, ( Stenella frontalis ) with one (1) school of 54 individuals, bottlenose dolphin ( Tursiops trucantus ) with one (1) school of 32 individuals, Common dolphin ( Delphinus delphis ) with four (4) schools of 452 individuals and (3) schools of Atlantic hump-backed dolphin ( Sousa teuszii ) of 32 individuals. Sighting rate of 5.7 x 10 -2 school/hr was estimated for schools while the sighting rate for individuals was estimated at 2.83 individual/hr. The results suggested that the Lagos coast is rich in delphinid biodiversity, which needs to be quantified more accurately during further research. Keywords : Sightings, Oceanic dolphins, abundance, species richness, behaviour, Nigeria.

상용코드를 이용한 다방향 불규칙파중 실습선의 종운동해석

본 연구에서는 실습선의 다방향 불규칙파중 종방향 운동응답특성을 선형 스트립이론에 기초한 상용코드(MAXSURF v.16)를 이용하여 해석하였다. 해석에 앞서 상용코드의 검증을 위해 파나막스급 컨테이너선에 대해 실험조건과 동일한 선형과 해석조건을 적용하여 계산한 결과와 기 계산된 결과(Flokstra, 1974)가 상호 유사한 경향을 얻어 해석의 신뢰성을 확보하였다. 계산조건으로는 Fn=0.257에서 파랑외력을 ITTC 파스펙트럼에 기초한 뷰포트 스케일 5(<TEX>$\bar{T}=5.46$</TEX>, <TEX>$H_{1/3}=2m$</TEX>)의 파스펙트럼을 산출하였고, 조우각은 선수사파(Head & bow seas, <TEX>$150^{\circ}$</TEX>)를 적용하여 상하동요(Heave)와 종동요(Pitch)의 선체운동응답스펙트럼을 해석하였다. 다방향 불규칙파에 대한 운동응답스펙트럼은 선수사파에서 상하동요의 경우는 미소하게 단파정파에서 높은 스펙트럼 분포를 보이고 종동요의 경우는 장파정파에서 높게 나타났다. This study gives the vertical motion analysis in multi-directional irregular waves using a commercial code(MAXSURF v.16) based on linear strip theory for a training ship. To verify the commercial code prior to the analysis, we guarantees the reliability of this paper's results using the commercial code by comparing with the results(Flokstra, 1974) of same hull and experimental conditions on a Panamax container. The analysis conditions are Beaufort wind scale No. 5(<TEX>$\bar{T}=5.46$</TEX>, <TEX>$H_{1/3}=2m$</TEX>) based on ITTC wave spectrum, encounter angle Head & bow seas(<TEX>$150^{\circ}$</TEX>) and Froude number Fn=0.257. Finally, we calculates heave RAO, pitch RAO and obtains the result of ship's response spectra for heave and pitch motions. In the motion response spectrum under the multi-directional irregular waves, heave motion reacts slightly high in short-crested waves and pitch motion reacts high in long-crested waves.

Field measurement and analysis of turbulence coherence for Typhoon Nuri at Macao Friendship Bridge

For the purpose of investigating the turbulent and spatial coherent characteristics of strong wind during typhoon landing period, two 3-dimensional ultrasonic anemometer stations were set up 30 m horizontally apart on the Macao Friendship Bridge to caputure the turbulent wind velocities of Typhoon Nuri. Based on the reliable and representative field measured data, the mean wind speed and direction, turbulence intensity, turbulence integral scale, turbulence power spectra, spatial correlation coefficient and coherence function were statistically evaluated. The field measurement analysis have presented the following results: 1) Two anemometer stations provided consistent results. The mean wind speed variation in time domain presented typical M-shape curves. The strong wind (10-minute mean wind speed higher than 8th grade in Beaufort wind scale) direction changed in a big range up to 122-degrees-angle, indicating the field measurements scoped over the typhoon landing period. 2) The ratio of the longitudinal, lateral and vertical turbulence intensities of the strong wind in the typhoon eye wall region was 1:0.96:0.36. Compared with the code defined ratio 1:0.88:0.5, the lateral component was larger and the vertical component was smaller. 3) The value of integral scale increased when the eye wall of Typhoon Nuri passed over the field measurement site. Before the center of Typhoon Nuri arrived, the integral scale of the strong typhoon wind was about twice compared with that for the non-typhoon wind. 4) The spatial correlation of the turbulent wind, coherence function curve and the decay factor had significant differences at different times during the typhoon process. In the eye wall of the typhoon, the horizontal spatial correlation was relatively strong and horizontally spatial correlation spectrum decayed slower with frequency increase. The minimum regressed coefficient C in coherence function model was 4.67, which is lower than the code defined low limit. The maximum decay factor was 27.75 which is larger than the code defined upper bound. The strong wind characteristic parameters of Typhoon Nuri mentioned above partly represented the turbulent and spatial coherent characteristic during strong typhoon wind period.

Observing animal behaviour: design and analysis of quantitative data

1. The power of observation 2. Asking the right question 3. When all you need is one 4. Three principles of observational design 5. The selective observer 6. Down to detail 7. Observing in zoos, on farms, and in the wild 8. Analysing observations 9. Further observations 10. Observing the Future Appendix 1: Some random numbers Appendix 2: Power and sample size Appendix 3: Beaufort wind scale

철도차량의 승강장 통과시 발생하는 공기역학적 영향에 대한 실험적 연구

The aerodynamic effect on platform during the train passage, the results of field test on the high-speed railway platform are discussed and the whole test results and conclusions are synthesized. The field test for the high-speed railway have been conducted on the Osong temporary platform in the newly constructed Seoul-Busan high-speed line and total 12 measurements have been conducted for G7 train and KTX train. The results shows that the high-speed trains have similar aerodynamic characteristics and have far better characteristics referring to the conventional trains such as Saemaul and Mugungwha trains. To discuss the actual aerodynamic effects on the platform at its own operational speed, Beaufort wind scale have been introduced and the criteria for the safety on railway platform has also been discussed.

実務者による大洋航海の航路選定シミュレーションと遭遇する気象・海象の特徴

In the weather ship's routing, it is very important to take account of the permission of the encountered wind speed and wave height and functionize them in weather ship's routing simulation models. To clarify the navigators' permission of encountered maximum wind speed and wave height in the ship's routing simulation, the questionnaire and the routing simulation were made to navigators of ripe experience. According to the questionnaire, for the safety navigation the permission of the maximum wind speed was the Gale rank in the Beaufort wind scale. Navigators had two permission of the maximum wave heights of 5 to 8m and 10 to 12m. From the results of the weather routing simulation by navigators using the optimum weather routing soft ware, for the safety navigation the encountered maximum wind speed and wave height were 30 to 40 knots and 7m at against winds and waves, 30 knots and 5 to 8m at lateral winds and waves, and 40 knots and 11m at following winds and waves, respectively.

The Facts on File weather and climate handbook

With the topics of weather and climate increasingly at the forefront of world attention, it is important to understand the relevant terms, definitions, and phenomena that one may be familiar with. Including more than 2000 entries, this handbook offers basic information about atmospheric processes, the sciences of climatology and meteorology, and the people who have made their mark in these disciplines. Topics covered include: acid rain, Beaufort wind scale; cooling degree days; glacial period; ice storm; mean temperature; sunspot; temperature-humidity index; veil of cloud; and zone of maximum precipitation.

Sealife: A Complete Guide to the Marine Environment

Part 1 Oceanography and marine biology: historical introduction evolution of the planet, life and oceanographic processes the physical and chemical nature of oceans water movements and oceanic circulation patterns. Part 2 Biology of marine environments: the pelagic environment plaktonic systems of surface waters other aspects of pelagic life benthic environments coastal sealife ecology shoreline environments estuaries and saltmarshes mangroves kelp forests seagrass meadows coral reefs summary - the marine ecosystem. Part 3 Identifying marine life - Part One - invertebrates (plates 1-8). Part 4 Marine invertebrates: structural support locomotion feeding defence and camouflage parasitism, commensalism and symbiosis sensory perception reproduction larvae and settlement evolution. Part 5 Identifying marine life - part two - vertebrates (plates 9-56). Part 6 Evolution of the vertebrates: the chordates and vertebrate ancestry early-palaeozoic vertebrates evolution of cartilaginous fishes evolution of bony fishes evolution of other vertebrates. Part 7 Marine fishes: jawless or cyclostome fishes (agnatha) cartilaginous fishes (chondrichthyes) sharks and rays chimaeras bony fishes (osteichthyes) cartilaginous fishes factsheet bony fishes factsheet. Part 8 Marine reptiles: crocodiles turtles and terrapins marine lizards marine snakes turtle factsheet. Part 8 Seabirds: taxonomy distribution and movements physiology and adaptations morphology and plumage food and feeding breeding status and conservation seabird factsheet. Part 9 Cetaceans: evolution taxonomy habitats and distribution food and feeding swimming respiration and diving senses life history stranding whales and man whale factsheet. Part 10 Sirenians: taxonomy and distribution swimming and diving diet behaviour and orientaton reproduction conservation. Part 11 Pinnipeds: evolution, natural history seal factsheet. Part 12 Marine otters. Part 13 Polar bear. Part 14 Reference section. Part 15 Observing, recording equipment collecting and sampling equipment observations and record-keeping other observational methods equipment list recording sheets. Appendices: the metric system and conversion factors SI units and scientific notation roots, prefixes and suffixes Beaufort wind scale.

THE BEAUFORT WIND SCALE…somewhat revised

WeatherVolume 44, Issue 3 p. 130-130 THE BEAUFORT WIND SCALE…somewhat revised Geoffrey Ball, Geoffrey Ball Sutton ColfieldSearch for more papers by this author Geoffrey Ball, Geoffrey Ball Sutton ColfieldSearch for more papers by this author First published: March 1989 https://doi.org/10.1002/j.1477-8696.1989.tb06996.xAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume44, Issue3March 1989Pages 130-130 RelatedInformation

On the Stern Flare Impact Pressure of RORO Ship

The after body of RORO ship or car ferry is characterized as follows; the frame line under water plane is very fine in order to improve the performance of propulsion, but the frame line upper water plane is very fat so as to take the broader deck area. Therefore the sectional form near the water plane becomes flat, and the angle between the water plane and the transverse section of ship is smaller than the other ship. These ship may suffer from the wave impact pressure on the stern flare. For this reason, the experimental and analytical studies on the stern flare impact pressure were carried out, and following results were obtained.(1) The fairly good agreement was found between the impact pressure coefficients obtained from the experiment in regular waves with those by Wagner's method. The magnitude of the coefficient was about 1020.(2) The maximum impact pressure which was predicted in irregular head waves from 3 to 11 Beaufort wind scale was about 2030 t/m2 for actual ship. This magnitude is smaller than the bow flare impact pressure, but the probability of occurrence of impact pressure is large. So it seems to be probable that the noise and fatigue due to transient vibration induced by the impact force becomes a problem.