A review of heat transfer data for single circular jet impingement

Jambunathan, K.; Lai, Eugene; Moss, Michael A.; Button, B. L.

doi:10.1016/0142-727x(92)90017-4

Cited by 1,007 publications

(374 citation statements)

References 21 publications

Supporting

Mentioning

340

Contrasting

Unclassified

Order By: Relevance

“…Table 1 shows the values of the parameters that were investigated. The values of both the local and average Nusselt numbers are considered to be functions To confirm the accuracy of the present work, the value of the steady jet Nusselt number versus Reynolds number was plotted and compared to the results of several previous researchers work as reported by Jambunathan et al [10] . Figure 2 shows that the measured Nusselt numbers for the steady jet are comparable with previous experiments.…”

Section: Methodsmentioning

confidence: 99%

Effect of Pulsating Circular Hot Air Jet Frequencies on Local and Average Nusselt Number

Zulkifli¹,

Sopian²,

Abdullah³

et al. 2008

American J. of Engineering and Applied Sciences

View full text Add to dashboard Cite

Abstract:The study was carried out to determine the effect of pulsating frequencies on the local and average heat transfer characteristic of a heated circular air jet. The velocity profile of a heated circular pulsating air jet was measured in the first part of the study. The same set-up was used to measure the heat flux of the pulsating jet impinging on a wall. The heat flux of the heated air jet impinging on the plate was measured using a heat flux microsensor at different radial positions. Measurement of the heat flux was used to calculate the average and local Nusselt Number for different pulsating frequencies and at different flow Reynolds Number. The pulsating frequencies were between 10-80 Hz and the Reynolds number used were 16 000, 23 300 and 32 000. Results obtained show that the local Nusselt number calculated were higher at all radial position away from the stagnation point. The pulsed jet Nusselt number was higher than the average steady jet Nusselt number for all values of frequencies due to the higher localised heat transfer. The higher Nusselt number obtained at localized radial positions can be due to the higher instantaneous velocity as was shown from the velocity profile plotted in the first part of the experiment. Enhanced turbulence intensity found was due to the pulsed jet.

show abstract

Section: Methodsmentioning

confidence: 99%

Effect of Pulsating Circular Hot Air Jet Frequencies on Local and Average Nusselt Number

Zulkifli¹,

Sopian²,

Abdullah³

et al. 2008

American J. of Engineering and Applied Sciences

View full text Add to dashboard Cite

show abstract

“…Previous numerical studies of impinging jets have concentrated on turbulence or code performance. Jambunathan [6] reviewed heat transfer data for circular impingement jets and found that the configuration can have a large effect on heat transfer rates. Differences in experimental conditions could then lead to seemingly contradictory conclusions.…”

Section: Background 21 Impinging Jetsmentioning

confidence: 99%

Exploration of a horizontal confined impinging heated jet using both experimental and numerical methods

Fahey¹,

Wakes²,

Shaw³

2007

The International Journal of Multiphysics

View full text Add to dashboard Cite

“…In the fully developed zone, the centre velocity decreases quickly due to strong mixing between the jet and surrounding air. In this region, jet attains a self-similar behaviour and the mean velocity profile can be approximated with a Gaussian profile (Jambunathan et al, 1992). As the jet approaches the wall, the flow is deflected from the axial direction and then turns, known as the impingement region.…”

Section: Impinging Jetmentioning

confidence: 99%

“…In the potential core zone, the centreline velocity of jet remains constant and the turbulence level is relatively low. Typically, the length of the zone varies between 6 and 7 diameters or slot widths downstream of the nozzle, depending on exit conditions of the velocity and turbulence intensity (Jambunathan et al, 1992). There is a shear layer between the potential core and the surrounding air, and the turbulence intensity in the shear layer is higher while the mean velocity is lower than in the potential core zone.…”

Section: Impinging Jetmentioning

confidence: 99%

Experimental and numerical investigations of a ventilation strategy – impinging jet ventilation for an office environment

Chen¹

2014

View full text Add to dashboard Cite

A well-functioning, energy-efficient ventilation system is of vital importance to offices, not only to provide the kind of comfortable, healthy indoor environment necessary for the well-being and productive work performance of occupants, but also to reduce energy use in buildings and the associated impact of CO 2 emissions on the environment. To achieve these goals impinging jet ventilation has been developed as an innovative ventilation concept.In an impinging jet ventilation system, a high momentum of air jet is discharged downwards, strikes the floor and spreads over it, thus distributing the fresh air along the floor in the form of a very thin shear layer. This system retains advantages of mixing and stratification from conventional air distribution methods, while capable of overcoming their shortcomings.The aim of this thesis is to reach a thorough understanding of impinging jet ventilation for providing a good thermal environment for an office, by using Computational Fluid Dynamics (CFD) supported by detailed measurements. The full-field measurements were carried out in two test rooms located in a large enclosure giving relatively stable climate conditions. This study has been divided into three parts where the first focuses on validation of numerical investigations against measurements, the second addresses impacts of a number of design parameters on the impinging jet flow field and thermal comfort level, and the third compares ventilation performance of the impinging jet supply device with other air supply devices intended for mixing, wall confluent jets and displacement ventilation, under specific room conditions. In the first part, velocity and temperature distributions of the impinging jet flow field predicted by different turbulence models are compared with detailed measurements. Results from the non-isothermal validation studies show that the accuracy of the simulation results is to a great extent dependent on the complexity of the turbulence models, due to complicated flow phenomena related to jet impingement, such as recirculation, curvature and instability. The f v  2 turbulence model shows the best performance with measurements, which is slightly better than the SST k-ω model but much better than the RNG k-ε model. The difference is assumed to be essentially related to the magnitude of turbulent kinetic energy predicted in the vicinity of the stagnation region. Results from the isothermal study show that both the SST k-ω and RNG k-ε models predict similar wall jet behaviours of the impinging jet flow. IVIn the second part, three sets of parametric studies were carried out by using validated CFD models. The first parametric study shows that the geometry of the air supply system has the most significant impact on the flow field. The rectangular air supply device, especially the one with larger aspect ratio, provides a longer penetration distance to the room, which is suitable for industrial ventilation. The second study reveals that the interaction effect of cooling ceiling, heat sources ...

show abstract

A review of heat transfer data for single circular jet impingement

Cited by 1,007 publications

References 21 publications

Effect of Pulsating Circular Hot Air Jet Frequencies on Local and Average Nusselt Number

Effect of Pulsating Circular Hot Air Jet Frequencies on Local and Average Nusselt Number

Exploration of a horizontal confined impinging heated jet using both experimental and numerical methods

Experimental and numerical investigations of a ventilation strategy – impinging jet ventilation for an office environment

Contact Info

Product

Resources

About