I am currently using gazeboimusensor plugin for my robot IMU sensor, but I am having some issue with understanding the output I am obtaining from the /imu topic.

When I spin my robot in a circle with an acceleration of 1 m/s^2 for a long period of time, I am receiving a negative output for my linear acceleration in the x direction but as far as I am aware, the linear acceleration in the x-direction should have been zero since my robot is spinning in a uniform circular motion.

I have never use an IMU sensor before so I am not sure what kind of output am I supposed to expect if my robot is spinning in circle. Is there anything that I might be missing?