First, it's spelled "Arucard"because the Japanese language is ridiculous. It was a translation error. How much sense does this make: "Dracura." That is "Arucard" backwards. It was supposed to be spelled "Alucard," and that's how it's pronounced in the english dub.
IIRC, l's are pronounced like r's in Japanese. There's a couple letters that don't exist in Japan as well.