Experimental Determination of Single and Two-Phase Cross Flow-Induced Forces on Tube Rows

The fluctuating forces induced by water and air/water cross flow on tube rows with pitch to diameter ratios of 1.5 and 3 were measured. Direct measurement of force spectra was possible because the tube was mounted on force transducers. The tubes within the test section were 300 mm in length and 30 mm in diameter. Results were obtained over ranges of void fraction and mass flux from 0 to 95 percent and 375 to 4125 kg/(m²s), respectively. A reasonably uniform spatial distribution of the void fraction was achieved through the use of an air/water mixing unit. The reported results include the power density spectra of the fluctuating forces and their corresponding force coefficient.