scholarly journals A Numerical Study on the Cooling Characteristics of Seeker Windows for Selecting Efficient Cooling Method

2017 ◽  
Vol 20 (2) ◽  
pp. 246-254
Author(s):  
Manshik Kim ◽  
Dong Min Lee
Keyword(s):  
Numerical Study ◽  
Cooling Method

A Novel Cooling Method for Turbine Rotor-Stator Rim Cavities Affected by Mainstream Ingress

2004 ◽  
Vol 127 (4) ◽  
pp. 798-806 ◽  
Author(s):  
Y. Okita ◽  
M. Nishiura ◽  
S. Yamawaki ◽  
Y. Hironaka
Keyword(s):  
Gas Flow ◽  
Numerical Study ◽  
Turbine Rotor ◽  
Rotor Blades ◽  
Significant Advance ◽  
Axial Distribution ◽  
Cooling Effectiveness ◽  
Cooling Flow ◽  
Cooling Method ◽  
Flow Phenomena

A combined experimental and numerical study of interaction between cooling flow and mainstream gas flow in a turbine rotor-stator rim cavity is reported. Particular emphasis is put on the flow phenomena in a rim cavity downstream of rotor blades. The experiments are conducted on a rig simulating an engine HP-turbine in which cooling effectiveness distributions as well as velocities, turbulence quantities, pressure, and temperature profiles are measured. Numerical calculation, especially at a full 3D, unsteady solution level, can lead to satisfactory predictions in fluid and mass transfer inside the cavity. Both experimental and numerical results indicate that large turbulence stresses near the rotor disk intensify turbulent diffusion across the cavity and consequently axial distribution of the cooling effectiveness inside the cavity becomes uniform. In order to obtain an adequate distribution of cooling effectiveness across the rim cavity and to suppress the turbulence level near the rotor surface for more efficient cooling, a novel cooling method is developed using numerical simulation. The disk-front and -rear cavities are then redesigned according to the new cooling strategy and integrated in the test rig. Experimental results verify a significant advance in cooling performance with the new method.

Investigation on Cooling System of High-Concentration Photovoltaic with Oscillating Heat Pipe

2012 ◽  
Vol 512-515 ◽  
pp. 84-89
Author(s):  
Wen Guang Geng ◽  
Ling Gao ◽  
Min Shao ◽  
Dong Ling Yuan ◽  
Xuan You Li
Keyword(s):  
Heat Flux ◽  
Temperature Distribution ◽  
Heat Pipe ◽  
Cooling System ◽  
Numerical Study ◽  
Navier Stokes ◽  
Turbulent Model ◽  
High Concentration ◽  
Oscillating Heat Pipe ◽  
Cooling Method

Cooling of concentration photovoltaic (CPV) cells with oscillating heat pipe was investigated numerically and experimentally. Based on Reynolds-averaged Navier-Stokes approach, a turbulent model was proposed in present work. Numerical study presented the temperature distribution under different heat flux and various outdoor conditions. CPV (with 12 suns concentration) system was experimentally studied, and the results show that the oscillating heat pipe begin operation at about 62°C, and CPV system could enhance electric power with a good cooling system under a high concentration light. The oscillating heat pipe cooling system, without air fan or pump, no power consumption, gives a uniform, reliable, simple and costless cooling method, oscillating heat pipe cooling is suitable for the high-CPV system.

A Novel Cooling Method for Turbine Rotor-Stator Rim Cavities Affected by Mainstream Ingress

2004 ◽  
Author(s):  
Y. Okita ◽  
M. Nishiura ◽  
S. Yamawaki ◽  
Y. Hironaka
Keyword(s):  
Gas Flow ◽  
Numerical Study ◽  
Turbine Rotor ◽  
Rotor Blades ◽  
Significant Advance ◽  
Axial Distribution ◽  
Cooling Effectiveness ◽  
Cooling Flow ◽  
Cooling Method ◽  
Flow Phenomena

A combined experimental and numerical study of interaction between cooling flow and mainstream gas flow in a turbine rotor-stator rim cavity is reported. Particular emphasis is put on the flow phenomena in a rim cavity downstream of rotor blades. The experiments are conducted on a rig simulating a engine HP-turbine in which cooling effectiveness distributions as well as velocities, turbulence quantities, pressure and temperature profiles are measured. Numerical calculation, especially at a full 3D, unsteady solution level, can lead to satisfactory predictions in fluid and mass transfer inside the cavity. Both experimental and numerical results indicate that large turbulence stresses near the rotor disk intensify turbulent diffusion across the cavity and consequently axial distribution of the cooling effectiveness inside the cavity becomes uniform. In order to obtain an adequate distribution of cooling effectiveness across the rim cavity and to suppress the turbulence level near the rotor surface for more efficient cooling, a novel cooling method is developed using numerical simulation. The disk-front and -rear cavities are then redesigned according to the new cooling strategy and integrated in the test rig. Experimental results verify a significant advance in cooling performance with the new method.

Numerical study of the low-frequency atomic dynamics in a Lennard-Jones glass

1998 ◽  
Vol 77 (2) ◽  
pp. 473-484 ◽  
Author(s):  
M. Sampoli, P. Benassi, R. Dell'Anna,
Keyword(s):  
Numerical Study ◽  
Low Frequency ◽  
Lennard Jones

Experimental and numerical study of the response of steel sheet Hopkinson specimens

2006 ◽  
Vol 134 ◽  
pp. 541-546 ◽  
Author(s):  
P. Verleysen ◽  
J. Degrieck
Keyword(s):  
Steel Sheet ◽  
Numerical Study

Numerical simulation of the tree higro-thermal response in forest fire environment

2020 ◽  
pp. 57-65
Author(s):  
Eusébio Conceiçã ◽  
João Gomes ◽  
Maria Manuela Lúcio ◽  
Jorge Raposo ◽  
Domingos Xavier Viegas ◽  
...  
Keyword(s):  
Forest Fire ◽  
Numerical Study ◽  
Thermal Response ◽  
View Factor ◽  
Tree Model ◽  
Pine Tree ◽  
Surface Temperatures ◽  
Fire Environment ◽  
Fire Front ◽  
Heat Exchanges

This paper refers to a numerical study of the hypo-thermal behaviour of a pine tree in a forest fire environment. The pine tree thermal response numerical model is based on energy balance integral equations for the tree elements and mass balance integral equation for the water in the tree. The simulation performed considers the heat conduction through the tree elements, heat exchanges by convection between the external tree surfaces and the environment, heat exchanges by radiation between the flame and the external tree surfaces and water heat loss by evaporation from the tree to the environment. The virtual three-dimensional tree model has a height of 7.5 m and is constituted by 8863 cylindrical elements representative of its trunks, branches and leaves. The fire front has 10 m long and a 2 m high. The study was conducted taking into account that the pine tree is located 5, 10 or 15 m from the fire front. For these three analyzed distances, the numerical results obtained regarding to the distribution of the view factors, mean radiant temperature and surface temperatures of the pine tree are presented. As main conclusion, it can be stated that the values of the view factor, MRT and surface temperatures of the pine tree decrease with increasing distance from the pine tree in front of fire.

NUMERICAL STUDY FOR THAILAND: MATHEMATICAL MODEL OF PRODUCTION AND LOGISTIC PLANNING FOR SUGARCANES USED IN BIOFUEL PRODUCTION

2013 ◽  
Author(s):  
Pancheewa Benjamasutin ◽  
◽  
Ponthong Rijana ◽  
Phongchayont Srisuwan ◽  
Aussadavut Dumrongsiri
Keyword(s):  
Mathematical Model ◽  
Numerical Study ◽  
Biofuel Production ◽  
Logistic Planning
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