The relation between wind speed and min required purge rate to avoid flare snuffing?

[bye106]

A calculation has been made to determine the min required purge rate for a flare riser:

Flare riser:
* Diameter: 50 in.
* Height: 91 m.
* Multi point sonic flare tip.
* Equipped with a velocity seal.
* Capacity: 1872 MMSCFD.

Purge gas
* 98% Methane.
* Min required purge rate (with seal) to prevent air infiltration as per API 521: 0.047 MMSCFD.
* Min required purge rate (without seal: more conservative) to prevent air infiltration as per API 521: 0.149 MMSCFD.

How ever, the operation team has refused to reduce the purge rate below 0.5 MMSCFD to avoid snuffing out especially in windy days (more than 12 m/s).

The question is that, what is the direct relation which considers the wind speed to establish the min required purge rate?

[YasnoSolnishko]

may be this helps
in the regulations of the Russian Federation there is such relation

velocity of purge gas in flare tip
no less than 0,05 m/s - if the flare with gas seal
no less than 0,9 m/s - without gas seal and density of purge gas 0.7 kg/m3
no less than 0,7 m/s - without gas seal and the purge gas is nitrogen

but it not depends on wind speed