Adnan, 29, spent last season at Russian top-flight club Rubin Kazan, where he made eight appearances.
The former Vancouver Whitecaps and Vejle BK player has eight goals in 85 international outings under belt.
He was an integral part of the Iraqi under-20 team which made it to the 2013 FIFA U-20 World Cup in Turkey, before suffering a shootout defeat against Uruguay.
Having started his overseas career with Turkish club Çaykur Rizespor in 2013, Adnan joined Serie A club Udinese in 2015, where he scored once in 65 games either side of a loan spell at Atalanta.
The Iraqi will join up with his new teammates in a training camp in Armenia.
Mes enjoyed an impressive run under ex-manager Mohammad Rabiei last season – finishing fifth in the Iranian league – but will have Saket Elhami as the new head coach for the start of the upcoming campaign.