# Wind Velocity and Wind Load

## Wind load on surface - Wind load calculator

When moving air - wind - is stopped by a surface - the dynamic energy in the wind is transformed to pressure. The pressure acting the surface transforms to a force

F_{w}= p_{d}A

= 1/2 ρ v^{2}A (1)

where

F_{w}= wind force (N)

A = surface area (m^{2})

p_{d }= dynamic pressure (Pa)

ρ = density of air (kg/m^{3})

v = wind speed (m/s)

Note - in practice wind force acting on a object creates more complex forces due to drag and other effects.

### Wind Load Calculator

* air density (kg/m ^{3})*

* wind speed (m/s) *

* area (m ^{2}) *

Wind Speed(m/s)Load Calculator! | Wind Load^{1)}(Pa)Load Calculator! |
---|---|

1 | 0.6 |

2 | 2.4 |

3 | 5.4 |

4 | 9.6 |

5 | 15 |

6 | 22 |

7 | 29 |

8 | 38 |

9 | 49 |

10 | 60 |

11 | 73 |

12 | 86 |

13 | 101 |

14 | 118 |

15 | 135 |

16 | 154 |

17 | 173 |

18 | 194 |

19 | 217 |

20 | 240 |

21 | 265 |

22 | 290 |

23 | 317 |

24 | 346 |

25 | 375 |

26 | 406 |

27 | 437 |

28 | 470 |

29 | 505 |

30 | 540 |

31 | 577 |

32 | 614 |

33 | 653 |

34 | 694 |

35 | 735 |

36 | 778 |

37 | 821 |

38 | 866 |

39 | 913 |

40 | 960 |

41 | 1009 |

42 | 1058 |

43 | 1109 |

44 | 1162 |

45 | 1215 |

46 | 1270 |

47 | 1325 |

48 | 1382 |

49 | 1441 |

50 | 1500 |

^{1)} density of air 1.2 kg/m^{3}

*1 m/s = 3.6 km/h = 196.85 ft/min = 2.237 mph**1 Pa =*1 N/m^{2}= 1.4504x10^{-4}psi (lb/in^{2})

### Example - Hurricane Wind Load acting on a Wall Surface

A hurricane with wind speed *35 m/s* is acting on a *10 m ^{2} *wall. The dynamic force can be calculated as

*F _{w} = 1/2 ρ v^{2} A *

* = 1/2 (1.2 kg/m ^{3}) (35 m/s)^{2} (10 m^{2})*

* = 7350 N*

* = 7.35 kN*

Or - from the table above the wind load per square metre is *735 N/m ^{2}. *The total load on the wall can be calculated as

*(735 N/m ^{2}) (*

*10 m*

^{2}) = 7350 N^{ }A hurricane acting on a *10 m ^{2}* wall creates a force equal to the weight of aprox.

*750 kg*.