No, in physics, it is not possible to accelerate without changing velocity. Acceleration is defined as the rate of change of velocity with respect to time. If an object's velocity remains constant, its acceleration is zero. Acceleration and velocity are closely related, and any change in acceleration will result in a change in velocity.
Velocity describes the speed of an object in a specific direction. If the speed or direction of an object changes, its velocity changes as well. Acceleration, on the other hand, refers to how quickly an object's velocity changes. To accelerate, an object must experience a change in velocity, either in terms of speed or direction.
It is important to note that velocity is a vector quantity, meaning it has both magnitude (speed) and direction. So even if the magnitude of the velocity remains constant, a change in direction would still result in a change in velocity and hence acceleration.