Van Gaal was officially unveiled to the media as David Moyes' successor on Thursday before United flew out to the United States for their pre-season tour.
Rafael was a member of the 23-man squad that departed for the US, where the club will contest the International Champions Cup against the Los Angeles Galaxy, Roma, Inter and Real Madrid.
Speaking to MUTV before leaving for Manchester Airport, the 24-year-old said he was looking forward to gaining a greater understanding of the Dutchman's tactics and formations as United attempt to return to the top four in the Premier League.
"I'm very excited," Rafael said. "Everyone's excited to see how he'll be both during games and away from it.
"It's clear [from watching Van Gaal in charge of Netherlands at the 2014 World Cup] that he likes to play with intelligent players. These types of players can change games and often shift from one formation to another. He seems very good at [doing] that.
"Some of his staff have been here from quite early on, so we have an idea of his methods, but we are all looking forward to finding out more from him."
United kick off their pre-season tour against the LA Galaxy on Wednesday, which is followed by games against Roma (June 26), Inter (June 29) and Real Madrid (August 2).
The club will return to Manchester to face Valencia in a friendly on August 12 before opening their Premier League campaign against Swansea City at Old Trafford four days later.
