Experimental and numerical research on portable short-throat flume in the field

• Portable short-throat flume as a new type of flow measurement device was developed.
• Experiments were conducted to analyze hydraulic performances of the flume.
• Simulated flow field in the flume by FLOW-3D agreed well with experimental results.
• Equations of upstream depth versus discharge were fitted out.

The use of portable short-throat flume in the field is an emerging technique developed for water discharges measurement of inlet in the field. Based on the principle of critical flow and RNG k–ε three-dimensional turbulence model along with the TruVOF technique, experiments and corresponding simulations were performed for 16 working conditions on the 76 mm width flume with discharges up to 40.01 L/s to determine its hydraulic performance. Hydraulic performance of the flume obtained from simulation analyses were later compared with observed results based on time-averaged flow field, flow pattern, Froude number and velocity distribution. Comparison yielded a solid agreement between results from two methods with relative error below ±10%. Regression models developed for upstream depth versus discharge under different working conditions were satisfying with the relative error of 9.16%, which met the common requirements of flow measurement in irrigation areas. Compared to the long-throat flume, head loss of portable short-throat flume in the field was significantly less. Further, head loss under the free flow condition was less than that under the submerged flow condition of portable short-throat flume with a flat base in the field.