Natural convection induced by unintended horizontal temperature distribution in a narrow-closed container heated from above

2022 ◽  
Vol 183 ◽  
pp. 122018
Author(s):  
Isamu Orikasa ◽  
Takuma Osada ◽  
Yuko Inatomi ◽  
Ichiro Ueno ◽  
Shinsuke Suzuki
Keyword(s):  
Natural Convection ◽  
Temperature Distribution ◽  
Closed Container

Airflow Simulation of the Huge Telescope Assemble

2010 ◽  
Vol 439-440 ◽  
pp. 880-883
Author(s):  
Fu Zhao ◽  
Ping Wang ◽  
Yan Jue Gong ◽  
Yu De Liu ◽  
Hong Bin Xin
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Natural Convection ◽  
Temperature Distribution ◽  
Velocity Field ◽  
Three Dimensional ◽  
Horizontal Line ◽  
Air Velocity ◽  
Turbulent Airflow ◽  
Dynamics Method

With the three-dimensional computational fluid dynamics method, the airflow effects over the huge telescope assemble is investigated in this article. The distributing of velocity field and natural convection are studied by modeling and simulating the turbulent airflow of the huge telescope. Numerical simulations show the best observation direction is the 90o angle between the main optics axis and the horizontal line in which the air velocity distribution is the least. And the air temperature distribution and uniformity around the telescope are also provided by simulation.

scholarly journals Natural Convection in a Trapezoidal Enclosure with Wavy Top Surface

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Pensiri Sompong ◽  
Supot Witayangkurn
Keyword(s):  
Natural Convection ◽  
Temperature Distribution ◽  
Flow Field ◽  
Element Model ◽  
Darcy Number ◽  
Model Builder ◽  
Small Influence ◽  
Study Results ◽  
Flow Intensity ◽  
Trapezoidal Enclosure

The effects of various parameters, Rayleigh number (Ra), Darcy number (Da), and wave amplitude (a), on natural convection inside a trapezoidal enclosure with wavy top surface are studied. The enclosure is filled with seawater having Prandtl number (Pr) of 7.2 and uniformly heated on bottom and partially heated on inclined boundaries. The flow field and temperature distribution are observed when interested parameters are chosen for Ra = 104, 105, and 106, Da = 10−5, 10−4, and 10−3, anda=0.9, 1, and 1.1. FlexPDE, a finite element model builder, is used to solve the governing equations to obtain the numerical results displayed by streamlines and isotherms. From the study results, convection motion is affected by different parameters in which the increase in flow intensity and temperature distribution can be seen at higher Rayleigh and Darcy numbers. The wavy top surface has small influence on the flow field and temperature distribution compared to the influence of Rayleigh and Darcy numbers.

Thermal behavior of natural convection flow in an inclined solar air heater

2020 ◽  
Vol 14 (4) ◽  
pp. 7569-7588
Author(s):  
Mohammed A. Neama ◽  
Ayad T. Mustafa
Keyword(s):  
Natural Convection ◽  
Temperature Distribution ◽  
Thermal Behavior ◽  
Tilt Angle ◽  
Convection Flow ◽  
Solar Air Heater ◽  
Natural Convection Flow ◽  
Collector Plate ◽  
Air Heater ◽  
Hot Air

The thermal behavior of hot air in a natural convection mode on a solar absorber-plate has not been, so far, modeled experimentally. The present work aimed to assess the performance of the inclined solar air heater [SAH] experimentally by investigating the temperature distribution field in the natural convection flow. The solar plate collector is designed based on the aspect ratio of length to height, L / H, of 6 and 12. The measurements are carried out for the collector tilt angles of 30°, 45°, 60° and 75°. The present investigation demonstrates the temperature distribution of hot air floated in an inclined channel of the SAH. The investigation showed 2D thermal stratification increases when increasing the distance along the collector plate, which looks clear in the SAH with a height of 10 cm. The results of the study show that the thickness of the thermal layers increases with increasing the tilt angle from 30˚ to 75˚. The reason dates back to increasing the buoyancy force of the hot air over the absorber. The results demonstrated that the air temperatures for the height of 0.1 m and 45˚ tilt angle are higher than that for the height of 0.2 m by 23%.

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