A theoretical study of wind-velocity and wind-direction in curved air-currents

AbstractSnowdrifting processes and the wind-velocity profiles around a collector and a blower snow fence were investigated in a cold wind tunnel. The purpose was to ascertain the effect of wind direction on drift control by snow fences. Three different cases were studied for both types of snow fence, and the resultant snowdrifts were compared. In the first case, the snow fence was perpendicular to the wind direction. In the second and third cases, it was tilted by 30° and 45°. When the collector snow fence was tilted, the amounts of snowdrift were much less than when the fence was perpendicular to the wind direction, because the area with low wind velocity was reduced to half behind the tilted fence. On the other hand, the blowing effect of the blower snow fence increased when it was set up at an angle to the wind direction. It is necessary to investigate the position where the blown snow is deposited by the tilted blower snow fence.

Download Full-text

Simple and Efficient Methods to Perform the Optimum Matching Between a Reciprocating Piston Pump and a Wind Machine

WSEAS TRANSACTIONS ON APPLIED AND THEORETICAL MECHANICS ◽

10.37394/232011.2020.15.24 ◽

2021 ◽

Vol 15 ◽

pp. 216-221

Author(s):

Mahmoud Mohamed El-Ghobashy El-Hagar

Keyword(s):

Wind Velocity ◽

Theoretical Study ◽

Piston Pump ◽

High Wind ◽

New Methods ◽

Cross Section Area ◽

Section Area ◽

Static Head ◽

Reciprocating Pump ◽

Starting Torque

One of the major problems facing the use of the wind driven reciprocating lift pump is the problem of starting. The required starting torque of the pump is at least three times the average torque. This means that the pump will need a high wind velocity just to be started, after that it will continue to operate at a lower wind velocity because of the lower average torque, provided that there is enough inertia in the system. For this reason, the torque characteristics of the wind turbine – reciprocating pump combination are very important. Thus, there is a real need to develop new methods in order to reduce this starting performance of the reciprocating pump. This paper presents a theoretical study to reduce the starting torque of a non-conventional reciprocating piston pump using new methods, for example, changing the wind machine parameters, such as the aerodynamics configuration of the rotor and blade elements, or by studying the effect of wind speed velocity on the starting torque. Also by changing the cross-section area of the piston or by changing the static head of the piston pump or by controlling the flow rate of the piston pump.

Download Full-text

A Spot Climate Recorder

Bulletin of the American Meteorological Society ◽

10.1175/1520-0477-37.4.160 ◽

1956 ◽

Vol 37 (4) ◽

pp. 160-165 ◽

Cited By ~ 2

Author(s):

Herbert B. Schultz ◽

Frederick A. Brooks

Keyword(s):

Environmental Factors ◽

Wind Velocity ◽

Wind Direction ◽

Agricultural Research ◽

Economic Advantage ◽

Storage Battery ◽

Field Equipment ◽

Meteorological Field ◽

Increasing Demand ◽

Current Drain

In agricultural research as well as in applied climatology as a whole, there is an increasing demand for portable meteorological field equipment capable of recording continuously more environmental factors than the conventional hygro-thermograph. The spot climate recorder described can register dry bulb, wet bulb, soil, and black globe temperatures, and wind direction and velocity on either daily or weekly charts, whichever is best for the climate survey. If desired, all these elements can be registered on one chart, but a set of two recorders has been found to be no more expensive and gives the economic advantage of making each useable separately. This is desirable for instance when a network of wind registering stations is needed (including 1 temperature each) but the complete record of moisture, radiation, etc. is sufficient at one station. The wind-recording circuits are designed for low-current drain on a 6-volt storage battery. Rather than draw on this battery to provide aspiration for the dry and wet-bulb thermometers, the wind velocity record is used to determine at which few hours the wet-bulb record may be unreliable.

Download Full-text

Nichtrotierende Meßeinrichtung zur gleichzeitigen Erfassung von Windgeschwindigkeit und Windrichtung / Non-rotating instrument for simultaneous measurement of wind velocity and wind direction

tm - Technisches Messen ◽

10.1524/teme.1990.57.jg.469 ◽

1990 ◽

Vol 57 (JG) ◽

Cited By ~ 1

Author(s):

A. Gräßer ◽

Α. Hühnergarth ◽

D. Schnotale

Keyword(s):

Wind Velocity ◽

Wind Direction ◽

Simultaneous Measurement

Download Full-text

Novel strategy for wide-range wind vector measurement using the hybrid CP/CTD heating mode and sequential measuring and correcting

PLoS ONE ◽

10.1371/journal.pone.0254256 ◽

2021 ◽

Vol 16 (7) ◽

pp. e0254256

Author(s):

Tian Wang ◽

Yunbo Shi ◽

Xiaoyu Yu ◽

Guangdong Lan ◽

Congning Liu

Keyword(s):

Wind Velocity ◽

Wind Direction ◽

High Velocity ◽

Measurement Instrument ◽

Wind Vector ◽

Velocity Range ◽

Vector Measurement ◽

Airflow Distribution ◽

Wide Range ◽

Novel Strategy

To improve the performance of wind sensors in the high velocity range, this paper proposes a wind measurement strategy for thermal wind velocity sensors that combines the constant power and constant temperature difference driving modes of the heating element. Based on the airflow distribution characteristics from fluid dynamics, sequential measurement and correction is proposed as a method of measuring wind direction. In addition, a wind velocity and direction measurement instrument was developed using the above-mentioned approaches. The test results showed that the proposed instrument can obtain large dynamic wind velocity measurements from 0 to 60 m/s. The wind velocity measurement accuracy was ±0.5 m/s in the common velocity range of 0–20 m/s and ±1 m/s in the high velocity range of 20–60 m/s. The wind direction accuracy was ±3° throughout the 360° range. The proposed approaches and instrument are not only practical but also capable of meeting the requirements of wide-range and large dynamic wind vector measurement applications.

Download Full-text