Error in bubble velocity measurement using 4-sensor void probe due to interface deformation

Experimental investigation on flow boiling bubble motion under ultrasonic field in vertical minichannel by using bubble tracking algorithm

“…Ref. [46] used a 5 μm needle sensor to measure the bubble velocity, and the maximum relative measurement error is about 15–20%. It can be seen that the measurement accuracy is higher than contact and achieved without the complicated debugging process or complex and cumbersome measurement equipment.…”