From what I've learned about Turkish names, the S is pronounced "sh." So Aysel, I believe, should be pronounced ay-SH-el.

Correction, as in Turkish only the letter 'ª' (an S with a tail below it) is pronounced 'sh'. Therefore Aysel is pronounced 'Eye - sel'.

I'm currently reading the book 'My heart & other black holes' by Jasmine Warga and the main character in this book is called Aysel. The pronunciation of the name in this book is 'Uh-zell'.