Comparison of one-dimensional models and a 1-D/2-D model for closed-loop thermosyphons with vertical heat transfer sections

Tropical cyclones moving inland over northern Australia are occasionally observed to reintensify, even in the absence of well-defined extratropical systems. Unlike cases of classical extratropical rejuvenation, such reintensifying storms retain their warm-core structure, often redeveloping such features as eyes. It is here hypothesized that the intensification or reintensification of these systems, christened agukabams, is made possible by large vertical heat fluxes from a deep layer of very hot, sandy soil that has been wetted by the first rains of the approaching systems, significantly increasing its thermal diffusivity. To test this hypothesis, simulations are performed with a simple tropical cyclone model coupled to a one-dimensional soil model. These simulations suggest that warm-core cyclones can indeed intensify when the underlying soil is sufficiently warm and wet and are maintained by heat transfer from the soil. The simulations also suggest that when the storms are sufficiently isolated from their oceanic source of moisture, the rainfall they produce is insufficient to keep the soil wet enough to transfer significant quantities of heat, and the storms then decay rapidly.

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A Numerical Treatment of One-dimensional Models of Radiative Heat Transfer in Co-current Tube Furnaces

IMA Journal of Applied Mathematics ◽

10.1093/imamat/13.2.169 ◽

1974 ◽

Vol 13 (2) ◽

pp. 169-185

Author(s):

I. P. GRANT ◽

D. ELLISON

Keyword(s):

Heat Transfer ◽

Radiative Heat Transfer ◽

Radiative Heat ◽

Numerical Treatment ◽

One Dimensional ◽

Current Tube ◽

Tube Furnaces ◽

Dimensional Models

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One-Dimensional Simulation and Experimental Investigation of the Shell-Integrated Condenser of the Underwater Closed-Loop Thermal Propulsion System

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.851.369 ◽

2016 ◽

Vol 851 ◽

pp. 369-376

Author(s):

Yong Jun Han ◽

Jun Lu ◽

Cheng Shi Yang ◽

Chao Bai ◽

Zhao Yuan Guo ◽

...

Keyword(s):

Heat Transfer ◽

Optimization Design ◽

Closed Loop ◽

Propulsion System ◽

Cross Sectional ◽

One Dimensional ◽

Unmanned Underwater Vehicles ◽

Simulation And Optimization ◽

Calculation Results ◽

Dimensional Simulation

In order to understand heat transfer of the shell condenser in the closed-loop thermal propulsion system of the unmanned underwater Vehicles, the one-dimensional thermal model based on the hull-integrated condenser with helix channels is developed. After this, experimental research is conducted. Through the experiment data and theoretical calculation results compared, the accuracy of the heat transfer mathematical model is verified, and the correlation formulas about heat transfer are developed. In addition, the impacts of three factors on the performance of the shell condenser are investigated, including cross-sectional area of the cooling channel, flow rate and temperature of inlet steam. The research results indicate that the model and the correlation formulas about heat transfer is reliability and accuracy, which can provide a theoretical basis for simulation and optimization design of the shell condenser.

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