An experimental investigation on comparison of synthetic and continuous jets impingement heat transfer

Tan, Xiaoming; Zhang, Jingzhou; Shan, Yongkui; Xie, Gongnan

doi:10.1016/j.ijheatmasstransfer.2015.06.065

Cited by 60 publications

(3 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The performance was greatly improved by controlling the flying path of the particles in a hot gas by the jets issued from triple concentric nozzle. By synthetic jet (Smith et al, 1998, Caruana et al, 2009, Tan et al, 2015:…”

Section: Active Jet Flow Controlmentioning

confidence: 99%

“…The synthetic jet with zero net mass flux generated by the alternate movement of a diaphragm is used for the flow control. Caruana et al (2009) used the plasma jet as a synthetic jet, and Tan et al (2015) showed the heat transfer enhancement of impinging jet by a synthetic jet. By plasma jet (Touchard, 2008, Hasebe et al, 2011, Caruana et al, 2013:…”

Section: Active Jet Flow Controlmentioning

confidence: 99%

See 1 more Smart Citation

Passive flow control of jets

Shakouchi

2020

Mechanical Engineering Reviews

View full text Add to dashboard Cite

One of the major purposes of fluid mechanics and engineering is to reduce the flow resistance caused by flow friction, flow separation, vortex generation, and other factors. To reduce or eliminate flow resistance, in general, flow control is performed either passively or actively. Passive flow control is performed by changing the flow channel or object shape a little and reducing the total flow resistance. On the contrary, active flow control uses a device requiring power, but it can perform various complex flow controls. In this paper, the passive flow control of jets is examined with flow characteristics, control methods, and some applications because jet flows include the essence of fluid dynamics, such as, boundary layer flow, turbulent flow, shear flow, and flow mixing. In particular, the effects of the nozzle shape, the tab, rib and vortex generator, and the orifice or notched orifice on the flow characteristics of sub-and supersonic jets are examined. Furthermore, the control and suppression of high speed jet noise by a chevron nozzle, some examples of active flow control, and other areas are examined. Globular formation of fine solid particles by flow control, lift control of airplane wings, and the flow control of a NOTAR helicopter without tail rotor are also addressed.

show abstract

Section: Active Jet Flow Controlmentioning

confidence: 99%

Section: Active Jet Flow Controlmentioning

confidence: 99%

Passive flow control of jets

Shakouchi

2020

Mechanical Engineering Reviews

View full text Add to dashboard Cite

show abstract

“…Synthetic jet actuators (SJAs) presented here belong to the classification of active-control devices. These devices have been applied in numerous fields, such as aircraft performance (Seifert et al , 1998; Glezer et al , 2005; Duvigneau and Visonneau, 2006; Ciuryla et al , 2007; Amir and Kontis, 2008; Farnsworth et al , 2008; Lin and Hsiao, 2013), electronics cooling (Mahalingam and Glezer, 2005; Pavlova and Amitay, 2006; Jang and Lee, 2014), fluid mixing (Xia and Zhong, 2013, 2014; Davis and Glezer, 1999), thermal management, and heat transfer (Akdag et al , 2013; Fanning et al , 2015; Iwana et al , 2015; Liu et al , 2015; Tan et al , 2015). More recently, the parameters used to optimize the control of SJAs have also attracted much attention.…”

Section: Introductionmentioning

confidence: 99%

Flow characteristics of two-dimensional synthetic jets under diaphragm resonance excitation

Lin¹

2019

AEAT

View full text Add to dashboard Cite

Purpose This paper aims to experimentally study the external flow characteristic of an isolated two-dimensional synthetic jet actuator undergoing diaphragm resonance. Design/methodology/approach The resonance frequency of the diaphragm (40 Hz) depends on the excitation mechanism in the actuator, whereas it is independent of cavity geometry, excitation waveform and excitation voltage. The velocity response of the synthetic jet is influenced by excitation voltage rather than excitation waveform. Thus, this investigation selected four different voltages (5, 10, 15 and 20 V) under the same sine waveform as experiment parameters. Findings The velocity field along the downstream direction is classified into five regions, which can be obtained by hot-wire measurement. The first region refers to an area in which flow moves from within the cavity to the exit of orifice through the oscillation of the diaphragm, but prior to the formation of the vortex of a synthetic jet. In this region, two characteristic frequencies exist at 20 and 40 Hz in the flow field. The second region refers to the area in which the vortices of a synthetic jet fully develop following their initial formation. In this region, the characteristic frequencies at 20 and 40 Hz still occur in the flow field. The third region refers to the area in which both fully developed vortices continue traveling downstream. It is difficult to obtain the characteristic frequency in this flow field, because the mean center velocities (ū) decay downstream and are proportional to (x/w)−1/2 for the four excitation voltages. The fourth region reveals variations in both vortices as they merge into a single vortex. The mean center velocities (ū) are approximately proportional to (x/w)0 in this region for the four excitation voltages. A fifth region deals with variations in the vortex of a synthetic jet after both vortices merge into one, in which the mean center velocities (ū) are approximately proportional to (x/w)−1 in this region for the four excitation voltages (x/w is the dimensionless streamwise distance). Originality/value Although the flow characteristics of synthetic jets had reported for flow control in some literatures, variations of flow structure for synthetic jets are still not studied under the excitation of diaphragm resonance. This paper showed some novel results that our velocity response results obtained by hot-wire measurement along the downstream direction compared with flow visualization resulted in the classification of five regions under the excitation of diaphragm resonance. In the future, it makes valuable contributions for experimental findings to provide researchers with further development of flow control.

show abstract

Enhancing heat transfer with a synthetic jet for thermal management applications

Shaker

2024

Heat Trans

View full text Add to dashboard Cite

This article explores the utilization of a synthetic jet as an approach to cool microelectronic devices, addressing their thermal management needs. The study includes both experimental measurements and numerical simulations to gain a comprehensive understanding of the heat transfer characteristics and fluid flow patterns generated by the synthetic jet actuator. The average Nusselt number (Nu) of the synthetic jet impinging flow with the dimensionless separation distances of the orifice to the heated surface (H/D) is investigated at different Reynolds numbers. A dynamic mesh scheme is employed in performing the simulations of the fluid domain to showcase the diaphragm's vibration and its deformation over time. The velocity profiles exhibit that the synthetic jet flow prompts the formation of two countervortices during every vibrating cycle of the diaphragm. The experimental results align closely with the predicted outcomes, indicating that the synthetic jet significantly enhances heat transfer by 3.1 times relative to the natural convection in the case of (H/D = 8.4) across different Reynolds numbers while maintaining low power consumption, a compact size, and a noise‐free operation.

show abstract

An experimental investigation on comparison of synthetic and continuous jets impingement heat transfer

Cited by 60 publications

References 34 publications

Passive flow control of jets

Passive flow control of jets

Flow characteristics of two-dimensional synthetic jets under diaphragm resonance excitation

Enhancing heat transfer with a synthetic jet for thermal management applications

Contact Info

Product

Resources

About