https://nova.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:37984 Tue 20 Jul 2021 19:18:32 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:35930 b = 2.70 and 3.52 mm) rise using the non-intrusive two-dimensional (2D) particle image velocimetry (PIV) at the low Taylor-Reynolds number (Re_λ) ranging from 12 to 60. Using the measured PIV velocity data, the instantaneous pressure fluctuations were estimated by integrating the full viscous form of the Navier-Stokes (N-S) equation and compared with three dimensional (3D) computational fluid dynamics (CFD) simulations. A spectral slope of -7/3 was found in the inertial subrange of the single-phase pressure spectrum. In contrast, the two-phase pressure spectrum exhibited a slope less steep than -7/3 in the inertial subrange because of the extra production of turbulence in the presence of bubble. For single-phase flow, the ratio of pressure integral length scale to the velocity integral length scale (L_p/L) was found to be a constant of about 0.67, and the pressure Taylor microscale (λ_p) was approximately 0.79 ± 0.03 of the velocity Taylor microscale (λ) for a low Reynolds number. The scaling ratio based on the single-phase experimental results were compared with existing theory and DNS results and found to accord well; however, these ratios deviate from theoretical values for two-phase flow. Also, the energy dissipation rate was evaluated based on the pressure spectrum and found the over-predicted (~ 31%) values relative to those calculated from the velocity spectrum.]]> Fri 19 Jun 2020 14:48:42 AEST ]]>