Experimental and CFD investigations of turbulent cross-flow in staggered tube bundle equipped with grooved cylinders

Abstract

In the present paper, an experimental and numerical simulation of the turbulent cross-flow in a staggered tube bundle with transverse and longitudinal pitch-to-diameter ratios of 3.8 and 2.1, respectively, are performed. The bundle consists of 16 PVC tubes of 40 mm outer diameter arranged in a staggered configuration. Each cylinder has two grooves on the external surface at 90° and 270°. The experiments are carried out using a subsonic wind tunnel. The pressure distributions along the tubes are determined for a variation of the azimuthal angle from 0° to 360°. The drag and lift forces are measured using the TE 81 balance. The drag coefficients are also deduced from the resulting pressure force in order to compare with smooth cylinder configuration. The use of the grooved cylinder shows a reduction on the drag forces. The steady-state Reynolds-averaged Navier–Stokes equations are solved using a finite-volume method where Spalart–Allmaras, k–e realizable and k–ω SST, turbulence models are used to produce a closed system of solvable equations. The staggered tube bundle geometry simulations are performed at steady conditions. An adapted grid using static pressure, pressure coefficient and velocity gradient, furthermore, a second-order upwind scheme were used. The obtained results show that the numerical predictions are in good agreement with the experimental measurements.