The word "ουλομένην" (= disastrous, cursed) is not used in modern Greek. You obviously found it in some ancient Greek text. (Probably in the preamble of Homer's Iliad).
«Μῆνιν ἄειδε, θεά, Πηληϊάδεω Ἀχιλῆος
"Sing, goddess,the disastrous Achilles' anger..."
Ancient Greek has been pronounced in various ways by those studying Ancient Greek literature in various times and places.
Greek speakers read and pronounce Greek texts from every period according to the contemporaneous local Greek pronunciation. That makes it easy to recognize the many words that have remained the same or similar in written form from one period to another.
Those who are not Greeks and study ancient Greek usually follow the pronunciation described by Erasmus, which tries to imitate the authentic pronunciation of ancient Greek (Attic dialect of the 5th century BC).
According to the Erasmian Pronunciation the combination ου is pronounced approximately as /ou/.
According to the modern Greek pronunciation, the combination ου is pronounced just as a simple /u/.
Therefore, a native Greek speaker nowadays using the current Greek pronunciation would not pronounce /v/ in the word "ουλομένην", as you mentioned.
Maybe you confuse the word "ουλομένην" with the word "βλαμμένη", which is used in modern Greek. It is a differnt word coming from a different root, but it sounds alike. it is pronounced as /vlamenee/ and it means "stupid", "fool".