Experiments on Measurement of Heat Transfer Rate of Gas Flow Through Microchannel with Constant Wall Temperature

This paper presents experimental results on heat transfer characteristics of turbulent gas flows though a micro-tube with constant wall temperature. The experiments were performed for nitrogen gas flows through a micro-tube with 242μm in diameter and 50 mm in length. The wall temperature was maintained at 5K, 20K and 30K higher than the inlet temperature by circulating water around the micro-tube, respectively. In order to measure heat transfer rate of gas flow through a micro-tube, the total temperature at a micro-tube exit was measured. The stagnation pressure was chosen in such a way that the Reynolds number ranges from 3000 to 12000. The outlet pressure was fixed at the atmospheric condition. The total temperature at the outlet, the inlet stagnation temperature, the mass flow rate, and the inlet pressure were measured. The heat transfer rates obtained by the present study are higher than those of the incompressible flow. This is due to the additional heat transfer near the micro-tube outlet caused by the energy conversion into kinetic energy. A correlation for the prediction of the heat transfer rate of the turbulent gas flow through a micro-tube was proposed.

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Total Temperature Measurement of Turbulent Gas Flow at Microtube Exit

ASME 2013 11th International Conference on Nanochannels, Microchannels, and Minichannels ◽

10.1115/icnmm2013-73180 ◽

2013 ◽

Author(s):

Chungpyo Hong ◽

Kyohei Isobe ◽

Yutaka Asako ◽

Ichiro Ueno

Keyword(s):

Heat Transfer ◽

Temperature Measurement ◽

Wall Temperature ◽

Gas Flow ◽

Constant Wall Temperature ◽

Circulating Water ◽

Total Temperature ◽

Flow Through ◽

Exit Mach Number ◽

Turbulent Gas Flow

This paper describes experimental results on total temperature measurement to obtain heat transfer characteristics of turbulent gas flow in a microtube with constant wall temperature. The experiments were performed for nitrogen gas flow through a microtube of 354 μm in diameter with 100 mm in length. The wall temperature was maintained at 310 K, 330 K, and 350 K by circulating water around the microtube, respectively. The stagnation pressure was chosen in such a way that the exit Mach number ranges from 0.1 to 1.0. In order to obtain heat transfer rate of turbulent gas flow through a micro-tube, the total temperatures of gas flowing out of a microtube exit were measured with the set of total temperature measurement attached to micro stage with position fine adjustment. The numerical computations based on the Arbitrary - Langrangian - Eulerian (ALE) method were also performed for the turbulent gas flow with the same conditions of the experiments. The results were in excellent agreement.

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Heat Transfer Characteristics of Compressible Laminar Flow Through Microtubes

Journal of Heat Transfer ◽

10.1115/1.4004645 ◽

2011 ◽

Vol 134 (1) ◽

Cited By ~ 6

Author(s):

Chungpyo Hong ◽

Takaharu Yamamoto ◽

Yutaka Asako ◽

Koichi Suzuki

Keyword(s):

Heat Transfer ◽

Wall Temperature ◽

Gas Flow ◽

Atmospheric Condition ◽

Stagnation Temperature ◽

Heat Transfer Characteristics ◽

Constant Wall Temperature ◽

Gaseous Flow ◽

Transfer Characteristics ◽

Flow Through

This paper describes experimental results on heat transfer characteristics of gaseous flow in a microtube with constant wall temperature. The experiments were performed for nitrogen gas flow through three microtubes of 123 μm, 163 μm, and 243 μm in diameter with 50mm in length, respectively. The wall temperature was maintained at 310 K, 330 K, and 350 K by circulating water around the microtube, respectively. The stagnation pressure is chosen in such a way that the exit Mach number ranges from 0.1 to 1.0. The outlet pressure was fixed at the atmospheric condition. The total temperature at the outlet, the inlet stagnation temperature, the mass flow rate, and the inlet pressure were measured. The numerical computations based on the Arbitrary-Lagrangian-Eulerian (ALE) method were also performed with the same conditions of the experiment for validation of numerical results. Both the results are in excellent agreement. In some cases, the total temperatures obtained by the present experimental study are higher than the wall temperature. This is due to the additional heat transfer from the wall to the gas near the microtube outlet caused by the temperature fall due to the energy conversion into the kinetic energy. A quantitative correlation for the prediction of the heat transfer rate of the gaseous flow in microtubes which had been proposed in our previous study (Hong and Asako, 2007, “Heat Transfer Characteristics of Gaseous Flows in a Microchannel and a Microtube with Constant Wall Temperature,” Numer. Heat Transfer, Part A, 52, pp. 219–238) was validated.

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Fully developed mixed convection of nanofluids in microtubes at constant wall temperature: Anomalous heat transfer rate and thermal performance

Advanced Powder Technology ◽

10.1016/j.apt.2016.11.019 ◽

2017 ◽

Vol 28 (3) ◽

pp. 721-731 ◽

Cited By ~ 3

Author(s):

S.J. Hosseini ◽

A. Malvandi ◽

S.A. Moshizi ◽

M. Zamani

Keyword(s):

Heat Transfer ◽

Mixed Convection ◽

Heat Transfer Rate ◽

Thermal Performance ◽

Wall Temperature ◽

Transfer Rate ◽

Constant Wall Temperature ◽

Anomalous Heat Transfer ◽

Anomalous Heat

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Heat Transmission Reinforcers Induced by MHD Hybrid Nanoparticles for Water/Water-EG Flowing over a Cylinder

Coatings ◽

10.3390/coatings11060623 ◽

2021 ◽

Vol 11 (6) ◽

pp. 623

Author(s):

Firas A. Alwawi ◽

Mohammed Z. Swalmeh ◽

Amjad S. Qazaq ◽

Ruwaidiah Idris

Keyword(s):

Heat Transfer ◽

Heat Transfer Rate ◽

Transfer Rate ◽

Volume Fraction ◽

Liquid Velocity ◽

Flow Characteristics ◽

Hybrid Nanoparticles ◽

Critical Parameters ◽

Heat Transmission ◽

Constant Wall Temperature

The assumptions that form our focus in this study are water or water-ethylene glycol flowing around a horizontal cylinder, containing hybrid nanoparticles, affected by a magnetic force, and under a constant wall temperature, in addition to considering free convection. The Tiwari–Das model is employed to highlight the influence of the nanoparticles volume fraction on the flow characteristics. A numerical approximate technique called the Keller box method is implemented to obtain a solution to the physical model. The effects of some critical parameters related to heat transmission are also graphically examined and analyzed. The increase in the nanoparticle volume fraction increases the heat transfer rate and liquid velocity; the strength of the magnetic field has an adverse effect on liquid velocity, heat transfer, and skin friction. We find that cobalt nanoparticles provide more efficient support for the heat transfer rate of aluminum oxide than aluminum nanoparticles.

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Total Temperature Measurements of Gaseous Flow at Micro-Tube Outlet

Volume 2: Theory and Fundamental Research; Aerospace Heat Transfer; Gas Turbine Heat Transfer; Computational Heat Transfer ◽

10.1115/ht2009-88109 ◽

2009 ◽

Author(s):

Takaharu Yamamoto ◽

Chungpyo Hong ◽

Yutaka Asako ◽

Koichi Suzuki

Keyword(s):

Heat Transfer ◽

Wall Temperature ◽

Gas Flow ◽

Atmospheric Condition ◽

Stagnation Temperature ◽

Constant Wall Temperature ◽

Gaseous Flow ◽

Circulating Water ◽

Total Temperature ◽

Exit Mach Number

This paper presents experimental results on heat transfer characteristics of gaseous flow in a micro-tube with constant wall temperature. The experiment was performed for nitrogen gas flow through a micro-tube with 166 micro meters in diameter and 50mm in length. The wall temperature was maintained at 305K, 310K, 330K and 350K by circulating water around the micro-tube, respectively. The stagnation pressure is chosen in such a way that the exit Mach number ranges from 0.1 to 1.0. The outlet pressure was fixed at the atmospheric condition. The total temperature at the outlet, the inlet stagnation temperature, the mass flow rate, and the inlet pressure were measured. The numerical computations based on the Aribitary - Langrangian - Eulerian (ALE) method were also performed for the same cases of the experiment for validation of numerical computation. The both results are in excellent agreement. The total temperatures obtained by the present study are slightly higher than those of the incompressible flow. This is due to the additional heat transfer near the micro-tube outlet caused by the temperature decrease due to the energy conversion into the kinetic energy. A quantitative correlation for the prediction of the heat transfer rate of the gaseous flow in a micro-tube was proposed.

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Dynamic simulation of the circulating fluidized bed loop performance under the various operating conditions

Proceedings of the Institution of Mechanical Engineers Part A Journal of Power and Energy ◽

10.1177/0957650919838111 ◽

2019 ◽

Vol 233 (7) ◽

pp. 901-913 ◽

Cited By ~ 2

Author(s):

Seongil Kim ◽

Sangmin Choi ◽

Jari Lappalainen ◽

Tae-Ho Song

Keyword(s):

Heat Transfer ◽

Fluidized Bed ◽

Heat Transfer Rate ◽

Dynamic Simulation ◽

Transfer Rate ◽

Gas Flow ◽

Circulating Fluidized Bed ◽

Operating Conditions ◽

Temperature Behavior ◽

Furnace Temperature

In a circulating fluidized bed boiler, the large thermal mass and flow characteristics of the solids strongly affect the transient response of the circulating fluidized bed loop temperature, which determines the heat transfer rate to steam flow. Therefore, it is essential to interpret the dynamic response of the solid behavior in the circulating fluidized bed loop for the stable and efficient operation of the circulating fluidized bed boiler. In this study, the dynamic simulation of the solid behavior along with the flue gas flow in a circulating fluidized bed loop was performed by applying the core-annulus approach for the solid-gas flow inside the furnace and selected models for other physical phenomena of the fluidized bed. The circulating fluidized bed loop of a commercial boiler was selected as the target system. Especially, the model simulates the characteristics of the solid behavior, such as the local solid mass distribution, and the solid flow inside the furnace and the circulating solid according to the various operating conditions. These aspects are difficult to measure and quantify in a real power plant. In this paper, the simulated furnace temperature behavior as the representative performance parameter of the circulating fluidized bed loop was discussed along with the qualitative operation experiences reported in the literature. The operating conditions include the feed rate of fuel and air, the particle size, the solid inventory and the solid circulation rate. Furnace temperature behavior was reproduced through the simulation for each operating case in the literature and was analyzed with the solid behavior along with the combustion rate and heat transfer rate of the circulating fluidized bed loop. The simulation enables quantitative evaluation of the effect of the solid behavior on the temperatures of the furnace and return part in the various operating conditions.

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