Running back Herschel Walker of Georgia is expected to win the 1982 Heisman Trophy that will be presented tonight at the Downtown Athletic Club in New York. The announcement will be made on national television (ABC) at 7.

Walker, a 6-foot-2, 220-pound junior, finished third in the voting as a freshman and second as a sophomore. He has led Georgia to the only perfect record among major teams this year and a No. 1 ranking with a rushing average of 159 yards and 15 touchdowns.

Another top candidate is Stanford's John Elway, a senior quarterback who ranks first among the nation's passers this season in total yardage (3,242 yards) and touchdowns (24). He finished his career with the most completions (774) in NCAA history. SMU running back Eric Dickerson, who has averaged 147 yards per game, is also a contender . . .

In other college news, one year after being named Big Eight football coach of the year, Don Fambrough has been fired by the University of Kansas. Fambrough's dismissal had been rumored for weeks. Kansas was 8-3 in 1981 and went to the Hall of Fame Bowl. This year, the Jayhawks were 2-7-2 . . .

George Perles, head coach of the Philadelphia franchise of the new United States Football League, has been approved as Michigan State's head coach. Perles, a Michigan State graduate, will succeed Frank (Muddy) Waters, who was fired.

Michigan State officials said Perles, a former assistant to Steelers Coach Chuck Noll, will get $95,000 a year for five years.