Experimental investigation of heat transfer and drag on surfaces coated with dimples of different shape

Leontiev, A. I.; Kiselev, N. A.; Vinogradov, Yu. A.; Стронгин, М. М.; Zditovets, A.G.; Burtsev, S. A.

doi:10.1016/j.ijthermalsci.2017.04.027

Cited by 55 publications

(12 citation statements)

References 32 publications

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“…The heat transfer enhancement of circular dimple is reported to be about 1.25 times that of the flat channel as Reynolds number increases while the friction factor remains at about 1.55 in the results obtained by Xie et al [6]. It highlights the fact that the drag and heat transfer performance of circular dimpled surfaces is highly sensitive to the dimpled geometry and flow conditions [7].…”

Section: Introductionmentioning

confidence: 59%

On Drag Reduction and Heat Transferin Turbulent Channel Flow over Circular Dimples: The Shift of the Deepest Point of Dimples

Khoo¹,

Chen²,

Tay³

et al. 2021

Proceedings of the 6th World Congress on Momentum, Heat and Mass Transfer

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In this study, the flow characteristics and enhanced heat transfer performance of circular dimples in a channel flow were numerically analysed and compared with a flat channel. The effect of shifting the deepest point of the dimples in turbulent flow on their drag and heat transfer performance are also discussed. The strength and extent of the induced recirculating flow is suppressed significantly when the deepest point is shifted downstream, enhancing the heat transfer performance of the dimpled wall. At the same time, the flow structure above the dimpled wall is manipulated by the geometry changes. The flow impingement on the dimpled wall increases drag; consequently, the power required to drive the flow is increased. A parametric study is conducted to optimize the shifting of the deepest point to maximize heat transfer performance while minimizing the drag increase.

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Section: Introductionmentioning

confidence: 59%

On Drag Reduction and Heat Transferin Turbulent Channel Flow over Circular Dimples: The Shift of the Deepest Point of Dimples

Khoo¹,

Chen²,

Tay³

et al. 2021

Proceedings of the 6th World Congress on Momentum, Heat and Mass Transfer

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“…The placement of dimples on poppet valve can be seen in fig. 2 for more better understanding of the geometry on which analysis is being carried upon, their configuration as well as their shape have a great effect on various parameters like drag, skin friction coefficient, standton number and reynolds number of the flow [8].…”

Section: Methodsmentioning

confidence: 99%

To Determine the Effect of Dimpled Poppet Valve on the Flow in Engine Cylinder by Port Flow Simulation

2018

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Intake system is one of the crucial sub-systems in engine, the geometrical configuration of the inlet ports and the valves and their opening schedule creates organized motions in the cylinder, known as swirl (about the cylinder axis) and tumble (orthogonal to the cylinder axis) which help in proper mixing of fuel and air. Surface texturing of intake valve can improve the performance of engine drastically by generating more swirl, turbulent kinetic energy and reducing the coefficient of skin friction in the valve proximity area. Making dimples on intake valve is one of the many ways in which surface texturing can be done and its effectiveness can be easily measured by conducting a steady-state port flow simulation on ANSYS IC fluent solver using standard k-omega model. Port flow analysis was carried on dimpled intake valve at a lift of 5mm for 5 dimple ratio ranging from 0.1 to 0.3 in steps of 0.05. The dimple depth-over diameter ratio is a very crucial parameter in determining the optimum geometry of dimple on which best results are obtained. The results showed that the maximum mass flow rate is obtained at dimple ratio of 0.2 with an increase of 0.005% over the simple intake valve and a 38.4% decrease in the area weighted average skin friction coefficient in valve proximity area was seen in case of dimpled valve.

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“…• covering the surface of the blades with a special relief ( types of surface relief that reduce aerodynamic drag and, consequently, noise in certain flow modes, see for example [16]);…”

Section: Environmental Problems Of Wind Power Plantsmentioning

confidence: 99%

Creating E-Courses for Learning the CAD Basics

Burtsev

Novitskiy

2020

ITM Web Conf.

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Article is devoted to the peculiarities of creating an electronic course on learning the basics of three-dimensional design of wind power plant elements using modern software systems. The iSpring Suite program was chosen as a course development tool. It has support for the SCORM 2004 format and extensive integration with office suites. In order to minimize problems with working in various distance learning systems, the course was divided into nine modules. The first module is dedicated to the basics of wind energy. The second module provides an overview of existing CAD programs. The third and fourth modules are dedicated to 2dimensional design. The fifth and sixth modules introduce commands for creating 3-dimensional parts from both other parts and 2-dimensional sketches. Module 7 is devoted to algorithms for creating assemblies from existing 3-dimensional parts. Module 8 and 9 represent the implementation of the multiplier/reducer Assembly algorithm from ready-made 3dimensional parts that are present in the course resources.

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Experimental investigation of heat transfer and drag on surfaces coated with dimples of different shape

Cited by 55 publications

References 32 publications

On Drag Reduction and Heat Transferin Turbulent Channel Flow over Circular Dimples: The Shift of the Deepest Point of Dimples

On Drag Reduction and Heat Transferin Turbulent Channel Flow over Circular Dimples: The Shift of the Deepest Point of Dimples

To Determine the Effect of Dimpled Poppet Valve on the Flow in Engine Cylinder by Port Flow Simulation

Creating E-Courses for Learning the CAD Basics

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