Numerical simulation of turbulent flow for calibration of cross‐correlation flow measurements

The cross‐correlation flow measurement technique, applied for measuring the coolant flow rate in a nuclear reactor, was calibrated with the use of numerical simulations of turbulent flow. The three‐dimensional domain was collapsed into two dimensions. With a two‐dimensional calculation of steady‐state flow with transient thermal characteristics the response of thermocouples to a temperature variation was calculated. By cross‐correlating the calculated thermocouple responses, the link between total flow rate and measured transit times was made. The reliability of the calibration was estimated at±4.6%. In addition, a measured velocity profile effect was successfully predicted.