Equivalent wind speeds

When details are given they should be checked, if only by comparison with equivalent wind speeds derived from first principles, to ensure that they are reasonable. Depending on the specified requirements, the wind speeds may or may not utilize gust wind speeds as in CPS (3) or mean hourly wind speeds, v, with applied gust factors. 

Based on the Proportion Law of hydro-mobility of hydrodynamics, with the standard wind tunnel, measured with the standard calibration of the Department, the relationship equation between the actual ventilator speed and the actual air velocity inside the wind tunnel was set up. It can be corrected traditionally with the anemometer readings and the actually tested air velocities for comparison, which has been improved to be the correction method of anemometer readings compared with the ventilator speeds, which is the equivalent wind speed law. 

Beaufort Scale Equivalent wind speeds and specifications for use on land and sea... 

Assume a continuous release of pressurized, hquefied cyclohexane with a vapor emission rate of 130 g moLs, 3.18 mVs at 25°C (86,644 Ib/h). (See Discharge Rates from Punctured Lines and Vessels in this sec tion for release rates of vapor.) The LFL of cyclohexane is 1.3 percent by vol., and so the maximum distance to the LFL for a wind speed of 1 iti/s (2.2 mi/h) is 260 m (853 ft), from Fig. 26-31. Thus, from Eq. (26-48), Vj 529 m 1817 kg. The volume of fuel from the LFL up to 100 percent at the moment of ignition for a continuous emission is not equal to the total quantity of vapor released that Vr volume stays the same even if the emission lasts for an extended period with the same values of meteorological variables, e.g., wind speed. For instance, in this case 9825 kg (21,661 lb) will havebeen emitted during a 15-min period, which is considerablv more than the 1817 kg (4005 lb) of cyclohexane in the vapor cloud above LFL. (A different approach is required for an instantaneous release, i.e., when a vapor cloud is explosively dispersed.) The equivalent weight of TNT may be estimated by... 

Figure 2 Variation of the gas transfer veloeity with wind speed. The units of transfer veloeity are equivalent to the number of em of the overlying air eolumn entering the water per hour (Taken from Bigg," with permission of Cambridge University Press)...

The use of dispersion-normalized data is equivalent to adjusting all ambient concentrations to the same dispersion conditions and assuming that the remaining variations in concentrations are due to variations in source emissions. Although this is a logical approach conceptually, it is not known at present what uncertainties are associated with the use of a dispersion factor calculated from a 7 A.M. determination of mixing height and wind-speed. 

Suppose that Jw, above some plant canopy reaches a peak value equivalent to 1.0 mm of water hour-1 during the daytime when the air temperature is 30°C and is 0.10 mm hour-1 at night when Tta is 20°C. Assume that during the daytime the relative humidity decreases by 20% across the first 30 m of turbulent air and that the eddy diffusion coefficient halves at night because of a reduced ambient wind speed compared to during the daytime. 

We conclude that over the continuum scale the determining parameters are the wind speed Uh and turbulence initial parameters of the cloud/plume when it reaches the top of the canopy or, equivalently, the virtual source at the level of the canopy. Using suitable fast approximate models for the flow field over urban areas (e.g. RIMPUFF, FLOWSTAR), the variation of the mean velocity and turbulence above the canopy can be calculated. The FLOWSTAR code (Carruthers et al., 1988 [105]) has been extended to predict how (Uc) varies within the canopy. Dispersion downwind of the canopy can also be estimated using cloud/plume profiles, denoted by Gc,w,GA,w which are shown in Figures 2.20 and 2.22. 

V,ef = basic wind speed converted to ft/sec Vz = mean hourly wind speed at hei t z, ft/sec z = equivalent height of vessel, ft = minimum design height, ft, from Table 3-3... 

Fast verification method of mining mechanical anemometers based on wind speed equivalent weight... 

ABSTRACT The problems in the current domestic use of the pitot tube combining micro-manometer to verify the mining mechanical anemometers were analyzed. Based on the structure principle of hydrodynamics, under the premise of the test with no violation of the orders anemometer verification, a new method based on wind speed equivalent weight to verify the anemometer was introduced. And the field test in the scene of the Key Laboratory of Hebei Province for Mine Disaster Prevention demonstrates that this method is a simple, fast, and accurate method to verify the mining mechanical anemometers within the expiration date of the wind tunnel. 

According to the Proportion Law of ventilator in hydrodynamics, the air flow in the wind tunnel and the ventilator speed is in direct proportion, so is the air speed of any point and the wind speed, for the cross-section of any point in the wind tunnel is constant. And the Verification of speed can be fast and accurate. Whereas the above analysis, the corresponding relation equation of them can be built up with determination of the air speeds to different ventilator speeds, improving the pitot tube micromanometer method, which is process-complicated and time-consuming with greater error in lower air velocity, into a method of calculating air velocity with determination of the ventilator speed, called the air velocity Equivalent weight method. 

About 25% of the USA has enough wind power to generate electricity at the cost of natural gas or coal-fired plants. Wind power accounts for less than 1% of the nation s energy supply, while coal and natural gas generate about two-thirds of the electricity. A study by Stanford University, California, USA, researchers measured wind speeds that hit turbines perched at the equivalent of a 20-storey building. Because wind is, intermittent wind power farms in locations with high wind speeds could be linked into energy networks that may provide a reliable and abundant source of electric power. 

The effects of the low air temperatures in the Transantarctic Mountains are magnified by wind which accelerates the loss of heat from the human body. This phenomenon is expressed quantitatively by the wind-chill scale (Rees 1993) that converts the measured temperature into an equivalent wind-chill temperature. For example, the arrow in Fig. 2.5a indicates that the measured air temperature of -10°C at a wind speed of 8 m/s corresponds to a wind-chill temperature of-20 C. In addition, a wind speed of 8 m/s in Fig. 2.5b is equivalent to a speed of 28.8 km/h. The wind-chill temperature also permits the definition of the discomfort index in Table 2.1. Accordingly, a wind-chill temperature of -20°C is perceived as being bitterly cold. Such conditions are not unusual during the austral sununer on the polar plateau and in the Transantarctic Mountains, except along the coast. 

Fig. 18.18 The internal temperature of a meteorite specimen placed on the bare ice of the Far Western ice field of the Allan Hills during December and January of 1985/86 was consistently higher than the air temperature and, on 2 days, actually exceeded the melting temperature of ice. The highest internal meteorite temperatures occurred on days when the wind speed decreased to zero. At these times, meteorite specimens can melt the ice on which they lie and are thereby exposed to liquid water that fills the cup-shaped depressions that forms around them. The wind speed is here expressed in terms of knots used by the US Navy and defined as one nautical mile per hour which is equivalent to 1.852 km/h (Adapted from Schultz 1986, 1990)...

For low wind speeds, the inclusion of information on the subjacent defects, due to either poor workmanship or to aging, that allow water to come into an apartment is currently under development. An equivalent permeability will be included in the program that will allow water leakage at low wind speeds. It is noteworthy though that water entering at low speeds is frequent in buildings in Florida so a consideration of this factor is important. 

Adequate probabilistic models of climatic actions and their combinations heavily depend on detailed measurement records of sufficient durations. Such data is available for wind actions, e.g. hourly values of wind speed/pressure. The direct measurements of Snow Water Equivalent values (SWE) (if any) are performed, e.g. in weekly or monthly periods. Daily values have to be recalculated from other meteorological data on various levels of approximation. Consequently, as a starting point for the development of a probabilistic model often only annual or/and monthly snow load maxima with percentage of month with snowfalls (in transitional climates) are available. This allows... 

Marine. Fine windswept chloride particles that get deposited on surfaces characterize this type of atmosphere. Marine atmospheres are usually highly corrosive, and the corrosivity tends to be significantly dependent on wind direction, wind speed, and distance from the coast. It should be noted that an equivalently corrosive environment is created by the use of deicing salts on the roads of many cold regions of the planet. 

The equivalent chill temperature or index shows the effect that wind speed has on perceived temperature. 

On shorter time scales, both riverine and atmospheric inputs can be highly episodic and are innately coupled, i.e., large precipitation events typically result in elevated stream transport. It has been shown (4) that the most prominent 10% of the precipitation events account for one third of the annual N wet deposition at Lewes. Similarly, for dry deposition, periods of high turbulence can lead to episodes of intensified deposition. Due to the differences between deposition velocity as a function of wind speed, the dry deposition associated with a wind speed of 20 m/s for 10 minutes a day would be equivalent to the deposition associated with an entire week at an average wind speed of 5 m/s (18). Such episodic behavior may have major implications in terms of ecosystem response, which in many instances may be more important than the cumulative loading. 

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