This might be attributed to a claim made by [17] that the presence of a favorable pressure gradient in duct flows tends to make Π smaller when compared with flat plate boundary layer flows. Hence, the logarithmic law may be valid much closer to the line of symmetry of the flow in the...
It is possible that differences in pressure, not evaluated in the experiments, play an important role in the evaluation of the drag from velocity profiles. High pressure values could reduce the drag; for this reason, pressure measurements are required in future experiments. To better understand the...
Pressure-based velocity measurements (Sect. 5.1), thermal anemometry (Sect. 5.2), and particle-based techniques (Sect. 5.3) represent the latter. In addition, particle image velocimetry (PIV, Sect. 5.3.2), planar Doppler velocimetry (Sect. 5.3.3), and molecular tagging velocimetry (Sect. 5.4...
The wind pressure at the outlet of the air duct serves as the input energy for accelerating the three-phase flow and can be expressed as follows: W = pvdAodt(17) Ao Fig. 3. Mathematical model of multiphase fluid velocity in liquid–solid–gas section of drill pipe. Scientific ...
Using this, and rearranging the formula for dynamic pressure to isolate for flow velocity, the flow velocity can be determined as a function of stagnation pressure and static pressure, as shown: Where pt is the stagnation pressure (total pressure) and ps is the static pressure. This shows ...
All pressure tappings were flushed with water to push out entrapped air prior to measuring. The correction of MacMillan58 was applied to account for velocity gradients, turbulence and near-wall effects59. In addition, the momentum exchange factor between the dispersed and continuous phase was ...
For the movement of gas bubbles, the constant drag force is used throughout the domain, which represents spherical bubble dynamics in the experimental study. The momentum transfer equation describes stress, gradient pressure, gravity, and the exchange of the range of motion between a dispersed and...
Obviously, to determine the acoustic energy in the duct, it is necessary to first obtain the expression of the unsteady surface pressure spectrum Δp0′r1′z1′ω′Δp0r2′z2′υon the vane surface. According to the three-dimensional lifting surface theory, the integral equation can be ...
In order to calculate these corrections it is necessary to know the directivity of the microphone turbulence screen, the propagation direction and energy of the duct modes and the flow velocity of the air in the duct. This paper derives a theoretical formula for the directivity of a microphone ...
George WK, Castillo L, Knecht P (1997) Zero-pressure-gradient turbulent boundary layer. Appl Mech Rev 50:689–730. https://doi.org/10.1115/1.3101858 Article Google Scholar Guo J (1998) Turbulent velocity profiles in clear water and sediment-laden flows, PhD Thesis. Colorado State University...