Let’s start with the air wind [http://www.etymonline.com/index.php?term=wind]. It’s from the Old English word wind, which stems from the Proto-Germanic wendas, the descendent of the Proto-Indo-European wento—blowing. It did used to be pronounced the same as the other wind (wynd) but in the eighteenth century, the shorter vowel version became more popular.
Now, let’s look at the “wynd” version, along with its past tense version wound, both of which have the expected pronunciations. Both come from another Old English word, windan—to twist. Its Proto-Germanic version is wendanan and its Proto-Indo-European is wendh, both meaning twist or turn (Interesting side note of the day: wander shares the same Proto-Indo-European origin word[http://www.etymonline.com/index.php?term=wander]).
Wound is (all together now) also comes from Old English [http://www.etymonline.com/index.php?term=wound]. Its origin word is wund, from the Proto-Germanic wundaz and Proto-Indo-European wen.
Why is it we in the English language have so many words that look the same and sound differently? Do we like to make things complicated? No, that’s not the American way. Actually, it all comes down to how we like to say stuff.
Languages are weird.