Preventing or removing contaminants in wellbore fluid using an acoustic actuator

An acoustic actuator for scale removal and prevention in a wellbore is described herein. For example, a system can include a tubing string deployed downhole in a wellbore. A downhole tool can be coupled to the tubing string. An acoustic actuator can be coupled to the tubing string and positioned proximate to the downhole tool. The acoustic actuator can generate an acoustic signal that can vibrate the tubing string to generate a fluidic disturbance in downhole fluid within the tubing string for removing contaminants from, or preventing formation of contaminants, on the downhole tool.