Entrance and exit effects on oscillatory flow within parallel-plates in standing-wave thermoacoustic system with two different operating frequencies

The Prospective of Particle Image Velocimetry (PIV) Measurement Velocity Profile in Thermoacoustic System

“…The layers are named the main and the secondary vortex layers, and they move with the cyclic flow and affect the shape of the velocity profile within the channel. The latest finding follows this by Allafi et al (Almukhtar et al, 2020), which presents the entrance and exit effects of oscillatory flow within a parallel-plate structure inside the resonator. Allafi and his team concluded that oscillatory flow across a parallel-plate structure is commonly found in the thermoacoustic system, and the effect of developing flow to the thermoacoustic performance should be seriously considered in the design.…”

“…However, the main drawback is that the software has a minimal ability to detect turbulence and streaming flow, which is crucial in investigating oscillatory flow. Meanwhile, CFD showed its ability to illustrate the streaming effect, as reported by Mohd Saat et al (Mohd Saat et al, 2019) and Allafi et al (Almukhtar Allafi et al, 2021), (Almukhtar et al, 2020).…”

Vibration-Induced Flow and Streaming in Oscillatory Flow of Thermoacoustics

“…The graphical representation in Figure 8 illustrates the investigation of the correlation between the drive ratio variant and the velocity of flow that was observed at a particular location positioned 270 mm from the center of the stack. This analysis involves a comparison between the measured velocity and the computationally computed velocity using the inlet boundary condition of the computational domain as was reported by Allafi and Saat [20] for the flow frequency of 23.6 Hz. Meanwhile, the drive ratio presents a ratio of the sound pressure at the pressure antinode and the mean pressure of the operation.…”

“…The soundwave travels along the resonator through the stack which is located inside the resonator. The resonator is built up as a straight duct based on the quarter wavelength setup as was reported in Allafi and Saat [20].…”

“…The pressure antinode location is a specific location within the resonator where the pressure exhibits its maximum intensity. According to the preliminary investigations prior to this study, the location of the pressure antinode is identified as the hard end of the quarter wavelength resonator where pressure sensor could be fitted to monitor the flow amplitude [18,20]. The mean pressure indicates the magnitude of the average air pressure contained within the resonator.…”