What are the common phrases in sports when you win the score?
Either saying 加油 or 加油加油 in a faster speed is a way to express the encouragement to oneself or the others. Also 哈（hà）, 耶（ye, Enligh word Yeah）, 呵（hè） can express the excitement when you win the score.

Actually, "chu" and "fa" are just sound and no specific Chinese characters for the meaning you want.