Numerical study of flow and heat transfer in a rectangular channel with pin fin arrays and back ribs

Kindra, Vladimir; Rogalev, Andrey; Osipov, Sergey; Zlyvko, Olga Vladimirovna; Vegera, Andrey

doi:10.29008/etc2021-615

Cited by 4 publications

(5 citation statements)

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“…The y+ parameter for the first prismatic cell at the channel wall was set to 1, for further simulation using the SST turbulence model. All parameters of the computational array were obtained by verifying the results of digital simulation of heat transfer in a channel with pins bathed in carbon dioxide [10]. The boundary conditions when conducting the digital simulation for two coolants were as follows: upstream of the channels, the total pressure and temperature of the coolant were set equal to 30 MPa and 200 °C for carbon dioxide coolant and to 5 MPa and 30 °C for nitrogen coolant.…”

Section: Methodsmentioning

confidence: 99%

“…The paper [10] presents the results of digital and experimental studies of the thermal and hydraulic characteristics of channels with various intensifiers (pin intensifiers; pin intensifiers with solid fins; and pin intensifiers with rounded fins), bathed in carbon dioxide coolant. This study describes the developed correlation dependences of the Nusselt number on the Reynolds number, which can be used in the development of a cooling system for carbon dioxide turbine blades.…”

Section: Introductionmentioning

confidence: 99%

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Study of the coolant type influence on the thermal and hydraulic characteristics of cooling channels for high-temperature turbine blades in an oxy-fuel energy system

Osipov

Lvov

Ostrovsky

et al. 2022

IOP Conf. Ser.: Earth Environ. Sci.

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Electricity consumption by people is increasing every year, followed by an increase in harmful emissions of carbon dioxide into the atmosphere during its generation. A promising solution to the problem of global pollution can be an oxy-fuel technology for energy production. It has been proven that the Allam cycle at an initial temperature of 1100 C is the most efficient oxy-fuel cycle. With a further increase in the initial temperature, the efficiency of this cycle decreases due to an increase in the relative coolant flow rate. This paper discusses the effect of the changeover from carbon dioxide to nitrogen coolant on thermal and hydraulic characteristics of cooling channels for the first-stage blade of a carbon dioxide turbine. We have found that, upon changeover from carbon dioxide to nitrogen cooling, the heat transfer coefficient decreases for a channel with pin intensifiers 1.3 to 1.65 times, for a channel with pin-and-dimple intensifiers, 1.65 to 1.77 times. We have also found that, upon changeover from pin intensifiers to pin-dimple ones, the heat transfer coefficient is increased for a cooling system using carbon dioxide coolant 2.2 to 2.5 times, whereas when using nitrogen coolant, the heat transfer coefficient remains unchanged. It has been also found that, to maintain a constant heat transfer coefficient upon changeover from carbon dioxide to nitrogen coolant, we should provide a 23.6% higher nitrogen flow rates compared to dioxide.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Study of the coolant type influence on the thermal and hydraulic characteristics of cooling channels for high-temperature turbine blades in an oxy-fuel energy system

Osipov

Lvov

Ostrovsky

et al. 2022

IOP Conf. Ser.: Earth Environ. Sci.

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“…where ∆P-the pressure drop, Pa; ρ-medium density, kg/m 3 ; V-medium velocity in the channel, m/s; L-channel length, m. Pressure drop ∆P in the reviewed area is determined as a difference of total pressures determined on surfaces for the collecting channel according to Equation (6).…”

Section: Numerical Simulation Methodsmentioning

confidence: 99%

“…Gas turbine units of various power classes have found wide application in the energy generation, the oil and gas sector, and a number of other industries [1][2][3]. An essential part of any modern gas turbine is the cooling system [4][5][6]. Traditionally, the following areas of the turbine blade airfoil are distinguished: the leading edge, the middle of the airfoil, and the trailing edge [7][8][9].…”

Section: Introductionmentioning

confidence: 99%

Asymmetric Method of Heat Transfer Intensification in Radial Channels of Gas Turbine Blades

Osipov

Rogalev

et al. 2022

Inventions

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Loop and semi-loop cooling schemes are widely used for the high-temperature gas turbine blades. In such schemes, the mid-chord airfoil parts are traditionally cooled by radial channels with ribbed walls. The blades with a small specific span, or “short” blades, have different heat flux amounts on pressure and suction sides, which results in a temperature difference in these sides of 100–150 °K. This difference causes thermal stresses and reduces the long-term strength margins. This paper presents a new method of heat transfer intensification in the ribbed radial cooling channels. The method is based on air streams’ injection through holes in the ribs that split channels. The streams are directed along the walls into the stagnation zones behind the ribs. The results of a 3D coolant flow simulation with ANSYS CFX code show the influence of the geometry parameters upon the channel heat transfer asymmetry. In the Reynolds number within a range of 6000–20,000, the method provides the heat transfer augmentation difference by up to 40% on the opposite channel walls. Test results presented in the criteria relations form allow for the calculation of mean the heat transfer coefficient along the channel length.

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“…for low-Reynolds models (SST, k − ω), which do not use near-wall functions, it is recommended to take y + within the range of 0 to 5 [5,6] due to the need to place the first near-wall cell in a viscous boundary layer; 2.…”

Section: Introductionmentioning

confidence: 99%

Computer Flow Simulation and Verification for Turbine Blade Channel Formed by the C-90-22 A Profile

et al. 2022

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Currently, software products for numerical simulation of fluid dynamics processes (Ansys, Star CCM+, Comsol) are widely used in the power engineering industry when designing new equipment. However, computer simulation methods embedded in proprietary software products make specialists choose grid settings, boundary conditions, and a solver providing the minimal deviation from experimental data with the maximal calculation speed. This paper analyzes the influence of the main grid settings and boundary conditions in the Ansys software package on the error in the computer simulation of flows in standard elements of power equipment and gives recommendations for their optimal choice. As standard elements were considered blade turbine channels formed by C-90-22 A profiles.

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Numerical study of flow and heat transfer in a rectangular channel with pin fin arrays and back ribs

Cited by 4 publications

References 0 publications

Study of the coolant type influence on the thermal and hydraulic characteristics of cooling channels for high-temperature turbine blades in an oxy-fuel energy system

Study of the coolant type influence on the thermal and hydraulic characteristics of cooling channels for high-temperature turbine blades in an oxy-fuel energy system

Asymmetric Method of Heat Transfer Intensification in Radial Channels of Gas Turbine Blades

Computer Flow Simulation and Verification for Turbine Blade Channel Formed by the C-90-22 A Profile

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