New Williams makes first appearance

The British outfit had previously only shown computer renderings of its new car, which were revealed by F1 Racing magazine.

Williams enjoyed a resurgence in 2014 as it became a regular podium finisher on its way to finishing third in the constructors' championship, and team boss Frank Williams said the aim is to continue that upward trajectory this year.

"After such a strong season in 2014 we are looking to continue the move back towards the front of the grid," he said.

"The move from ninth to third was a tough challenge, but ultimately every step up from now on will be even harder.

"I am confident that we have the appropriate personnel and talent in this team to make those steps."

Valtteri Bottas is scheduled to take driving duties on the first day of official testing in Spain on Sunday.