Prediction of Local Heat Transfer on a Rotating Disk By a Two-Equation Model of Turbulence

1977 ◽  
Vol 99 (1) ◽  
pp. 151-152 ◽  
Author(s):  
B. I. Sharma
Keyword(s):  
Heat Transfer ◽  
Local Heat Transfer ◽  
Rotating Disk ◽  
Local Heat ◽  
Equation Model

Local Heat Transfer From a Rotating Disk in an Impinging Round Jet

1986 ◽  
Vol 108 (2) ◽  
pp. 357-364 ◽  
Author(s):  
C. O. Popiel ◽  
L. Boguslawski
Keyword(s):  
Heat Transfer ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Velocity Ratio ◽  
Jet Impingement ◽  
Local Heat Transfer ◽  
Rotating Disk ◽  
Local Heat ◽  
Tube Diameter ◽  
Air Jet

The results of an experimental investigation of local convective heat transfer from the surface of a rotating disk in an impinging free round air jet, issuing from a long tube, are reported. Using a transient heat transfer method applied to the ring-shaped h-calorimeter (as a single lumped capacitance element) measurements of convective heat transfer rates were made for five impingement radius (fixed) to tube diameter ratios for a range of rotational and jet Reynolds numbers. In the pure impingement-dominated regime, where the rotation of the disk does not show an effect on heat transfer, the velocity ratio is ur/uj ≤ (1 − 2 × 10−4 Re2/3) (1 − 0.18 r/d), where ur = tangential velocity of the disk at the jet impingement radius r, uj = average exit velocity of jet, and d = jet tube diameter. In this regime, the local heat transfer on the rotating disk can be strongly enhanced by jet impingement. For ur/uj ⪞ 5, the effect of the jet impingement on heat transfer can be neglected. The discussion of the heat transfer results has been supported by smoke flow visualization.

Particle Image Velocimetry and Heat Transfer Measurements of a Disk at High Rotational Speeds

2002 ◽  
Author(s):  
N. Saniei ◽  
A. B. Olcay ◽  
X. Yan
Keyword(s):  
Heat Transfer ◽  
Particle Image Velocimetry ◽  
Flow Field ◽  
Particle Image ◽  
Local Heat Transfer ◽  
Rotating Disk ◽  
Disk Drive ◽  
Local Heat ◽  
Image Velocimetry ◽  
Back Calculation

Flow field and local heat transfer measurements were conducted on a rotating disk in an open environment for a variety of rotational speeds ranging from 1500 to 5500 rpm. Two-dimensional particle image velocimetry (PIV) measurements were conducted on the flow field above the surface of the rotating disk. Experiments were made on a rotating disk twice as large as a computer hard disk drive and therefore, the flow conditions may be comparable with a computer disk rotating with a speed up to 20,000 rpm. Velocity field, local heat transfer, and temperature distribution are presented as the result of this investigation. Transient liquid crystal technique was employed for heat transfer measurements, while a back calculation scheme was used to obtain the temperature distributions. Heat transfer measurements were made for r/R > 0.4 which excludes the central hub holding the disk assembly. Results reveals that heat transfer increases with a smaller slope near the corner of the hub, while it increases sharply near the outside edge of the disk.

Local Heat Transfer Distributions Within a Rotating Pin-Finned Brake Disk

2020 ◽  
Vol 142 (11) ◽  
Author(s):  
Michael D. Atkins ◽  
Frank W. Kienhöfer ◽  
Tian Jian Lu ◽  
Tongbeum Kim
Keyword(s):  
Heat Transfer ◽  
Thermal Stresses ◽  
Local Heat Transfer ◽  
Rotating Disk ◽  
Local Heat ◽  
Thermochromic Liquid Crystal ◽  
Brake Disk ◽  
Internal Surfaces ◽  
Rotating Reference Frame ◽  
Pin Fins

Abstract This study presents local temperature and heat transfer coefficient distributions obtained experimentally on the internal surfaces of a rotating pin-finned brake rotor at realistic rotation speeds for braking (i.e., N = 100–300 rpm). To this end, the thermochromic liquid crystal technique in a rotating reference frame was employed. The results demonstrate that the bulk airflow within the ventilated channel of a rotating disk follows a predominantly backward sweeping inline-like path between the pin fins. Internal local heat transfer is distributed nonuniformly on both inboard and outboard surfaces, with twice higher average cooling from the outboard surface than the inboard surface: this possibly exacerbates the thermal stresses, which leads to thermal distortion of the rotor (i.e., coning).

Convective Heat Transfer on a Rotating Disk With Transverse Air Crossflow

2010 ◽  
Vol 133 (2) ◽  
Author(s):  
Benjamin Latour ◽  
Pascale Bouvier ◽  
Souad Harmand
Keyword(s):  
Heat Transfer ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Transfer Problem ◽  
Convective Heat Transfer Coefficient ◽  
Local Heat Transfer ◽  
Rotating Disk ◽  
Reynolds Numbers ◽  
Local Heat ◽  
Spatio Temporal

In this study, the local convective heat transfer from a rotating disk with a transverse air crossflow was evaluated using an infrared thermographic experimental setup. Solving the inverse conduction heat transfer problem allows the local convective heat transfer coefficient to be identified. We used the specification function method along with spatio-temporal regularization to develop a model of local convective heat transfer in order to take lateral conduction and 2D geometry into account. This model was tested using rotational Reynolds numbers (based on the cylinder diameter and the peripheral speed) between 0 and 17,200 and air crossflow Reynolds numbers between 0 and 39,600. In this paper, the distribution of the local heat transfer on the disk allows us to observe the combined effect of the rotation and air crossflow on heat exchanges. This coupling is able to be taken into account in a correlation of mean Nusselt number relative to both Reynolds numbers.

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