Desiccant Dehumidification System for Space Radiant Cooling in Tropical Climate

2012 ◽  
Vol 622-623 ◽  
pp. 1575-1579
Author(s):  
T. Kiewkem ◽  
P. Chaiwiwatworakul ◽  
S. Chirarattananon
Keyword(s):  
Computer Program ◽  
Thermal Comfort ◽  
Simulation Study ◽  
Cooling System ◽  
Tropical Climate ◽  
Experimental Results ◽  
Radiant Cooling ◽  
Simulation Results ◽  
Good Agreement

This paper presents an experimental and simulation study on application of a rotating desiccant dehumidification system under a tropical climate. The system was used to dehumidify the ventilation air before supplying to a space where a radiant cooling system was installed to provide thermal comfort. In the study, a computer program of the desiccant system was coded and used to evaluate the system performances. The experimental results show good agreement with the results from coded program. Using the program, the simulation results demonstrate that the desiccant system can reduce and handle the load of the ventilation air. The results also show that in order to remove the whole latent load, the minimum regeneration temperature is 80°C.

scholarly journals Numerical Simulations of V-Shaped Plates Subjected to Blast Loadings: A Validation Study

2016 ◽  
Vol 10 (11) ◽  
pp. 203
Author(s):  
Mohd Zaid Othman ◽  
Qasim H. Shah ◽  
Muhammad Akram Muhammad Khan ◽  
Tan Kean Sheng ◽  
M. A. Yahaya ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Numerical Simulations ◽  
Variable Mass ◽  
Blast Loading ◽  
Experimental Results ◽  
Average Difference ◽  
Simulation Results ◽  
Blast Loadings ◽  
Carrier Vehicle ◽  
Good Agreement

A series of numerical simulations utilizing LS-DYNA was performed to determine the mid-point deformations of V-shaped plates due to blast loading. The numerical simulation results were then compared with experimental results from published literature. The V-shaped plate is made of DOMEX 700 and is used underneath an armour personal carrier vehicle as an anti-tank mine to mitigate the effects of explosion from landmines in a battlefield. The performed numerical simulations of blast loading of V-shaped plates consisted of various angles i.e. 60°, 90°, 120°, 150° and 180°; variable mass of explosives located at the central mid-point of the V-shaped vertex with various stand-off distances. It could be seen that the numerical simulations produced good agreement with the experimental results where the average difference was about 26.6%.

scholarly journals Thermal Comfort and Energy Analysis of a Hybrid Cooling System by Coupling Natural Ventilation with Radiant and Indirect Evaporative Cooling

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7825
Author(s):  
Pradeep Shakya ◽  
Gimson Ng ◽  
Xiaoli Zhou ◽  
Yew Wah Wong ◽  
Swapnil Dubey ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
Hybrid System ◽  
Natural Ventilation ◽  
Cooling System ◽  
Evaporative Cooling ◽  
Supply System ◽  
Hybrid Cooling ◽  
Air Supply ◽  
Radiant Cooling ◽  
Indirect Evaporative Cooling

A hybrid cooling system which combines natural ventilation with a radiant cooling system for a hot and humid climate was studied. Indirect evaporative cooling was used to produce chilled water at temperatures slightly higher than the dew point. With this hybrid system, the condensation issue on the panel surface of a chilled ceiling was overcome. A computational fluid dynamics (CFD) model was employed to determine the cooling load and the parameters required for thermal comfort analysis for this hybrid system in an office-sized, well-insulated test room. Upon closer investigation, it was found that the thermal comfort by the hybrid system was acceptable only in limited outdoor conditions. Therefore, the hybrid system with a secondary fresh air supply system was suggested. Furthermore, the energy consumptions of conventional all-air, radiant cooling, and hybrid systems including the secondary air supply system were compared under similar thermal comfort conditions. The predicted results indicated that the hybrid system saves up to 77% and 61% of primary energy when compared with all-air and radiant cooling systems, respectively, while maintaining similar thermal comfort.

The Influence of Oil Lubricated Journal Bearings on the Dynamics of Rotating Systems

1976 ◽  
Vol 190 (1) ◽  
pp. 627-633 ◽  
Author(s):  
H. McCallion ◽  
D. R. Wales
Keyword(s):  
Boundary Conditions ◽  
Computer Program ◽  
Translational Motion ◽  
Journal Bearings ◽  
Experimental Results ◽  
Oil Film ◽  
Rotating Systems ◽  
Film Boundary ◽  
Good Agreement

SYNOPSIS A computer program representing a shaft and rotor whirling in bearings which allows for realistic oil film boundary conditions and non-circular bearing profiles has been developed. It gave good agreement with experimental results published by Brown and France. With the aim of increasing understanding of the influence of bearing profile on system instability, the program calculates the timewise variation of the energy in translational motion supplied to the rotor by oil film forces. One case is illustrated.

SIMULATION STUDY ON BREAKDOWN BEHAVIOR OF FIELD-PLATE SiC MESFETs

2004 ◽  
Vol 14 (03) ◽  
pp. 884-889 ◽  
Author(s):  
HO-YOUNG CHA ◽  
Y. C. CHOI ◽  
LESTER F. EASTMAN ◽  
MICHAEL G. SPENCER
Keyword(s):  
Breakdown Voltage ◽  
Simulation Study ◽  
Two Dimensional ◽  
Plate Structures ◽  
Field Plate ◽  
Simulation Results ◽  
Good Agreement

The effects of field-plate structures on SiC MESFETs were investigated using two-dimensional simulations. The simulation results without a field-plate were in good agreement with the characteristics of fabricated SiC MESFETs. The breakdown voltage was increased by 80 % when the optimum field-plate was applied to the device with a 0.5 μm long gate and a 1 μm spacing between gate and drain; a breakdown voltage of 240 – 250 V was obtained from a 0.35 μm field-plate, while 140 V was obtained without a field-plate.

Stick-Slip Vibration Between Two Large Concentric Circular Discs in Rotational Contact With Multiple Point Loads

2003 ◽  
Author(s):  
M. Baleri ◽  
F. Sassani ◽  
P. L. Ko
Keyword(s):  
Experimental Results ◽  
Integral Model ◽  
Mathematical Representation ◽  
Multiple Point ◽  
Stick Slip ◽  
System Parameters ◽  
Modeling Simulation ◽  
Contact Loads ◽  
Simulation Results ◽  
Good Agreement

This paper presents a study of the stick-slip frictional phenomenon when large contact areas subjected to uneven contact loads are involved. The objective of the investigation is to gain better understanding of the phenomenon from experimental observations and to develop a mathematical representation that can be used for modeling, simulation and design purposes. A dynamic integral-model has been proposed and simulations have been carried out. The effects of various system parameters on the behavior of the system have been studied experimentally and analytically. The simulation results using the proposed integral-model are in good agreement with the experimental results. The latter also show that stick-slip vibrations can be influenced by the loading conditions.

A human thermal balance based evaluation of thermal comfort subject to radiant cooling system and sedentary status

2017 ◽  
Vol 122 ◽  
pp. 461-472 ◽  
Author(s):  
S. Gao ◽  
Y. Li ◽  
Y.A. Wang ◽  
X.Z. Meng ◽  
L.Y. Zhang ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
Cooling System ◽  
Thermal Balance ◽  
Radiant Cooling

Quintuple band circular monopole antenna with innovative 3-D printed PLA substrate for wireless applications

Frequenz ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ashraf E. Ahmed ◽  
Wael A.E. Ali ◽  
Sudipta Das
Keyword(s):  
Polylactic Acid ◽  
Monopole Antenna ◽  
Design Concept ◽  
Experimental Results ◽  
Printed Antenna ◽  
Wireless Applications ◽  
Innovative Technique ◽  
Compact Size ◽  
Simulation Results ◽  
Good Agreement

Abstract In this paper, a circular antenna with a 3-D printed substrate is introduced to achieve a multiband behavior. The circular antenna is matched using a key-shaped stub located on the perimeter of the designed antenna. The 3-DP circular antenna adopted the apollonian gasket technique to perform the multi-circular cuttings in the Polylactic Acid (PLA) substrate as an innovative technique to obtain quintuple bands. The proposed antenna is designed to operate for Bluetooth, WLAN, WiMAX, and other wireless applications in S-band and C-band. The designed antenna has a compact size of 61.1 × 43.6 × 1 mm3. The prototype of the suggested 3-D printed antenna is fabricated and measured to confirm the simulation results. A good agreement is evident between simulation and experimental results which validates the design concept.

Bond-Slip Numerical Simulation of Concrete and Gypsum Board

2011 ◽  
Vol 255-260 ◽  
pp. 3133-3136
Author(s):  
Quan Bin Zhao ◽  
Xin Liang Jiang
Keyword(s):  
Numerical Simulation ◽  
Constitutive Relation ◽  
Simulation Analysis ◽  
Experimental Results ◽  
Gypsum Board ◽  
Bond Slip ◽  
Pull Out ◽  
Simulation Results ◽  
Research Situation ◽  
Good Agreement

The characteristics and research situation of bond-slip performance at the inter face of concrete and other materials are introduced, and the bond-slip constitutive relation models are summarized at the same time. Through the load-slip curves obtained from the pull-out experiment of CFFP, the proposed bond-slip constitutive relation models are presenting, including the simple one. With the numerical simulation analysis of CFFP is carried out by the use of the proposed constitutive relation, while the numerical simulation results are in good agreement with the experimental results conducted before, which is feasible and can be applied to further research on CFFP.

Heat Transfer Investigation of an Additively Manufactured Minichannel Heat Exchanger

2019 ◽  
Author(s):  
Hamidreza Rastan ◽  
Amir Abdi ◽  
Monika Ignatowicz ◽  
Bejan Hamawandi ◽  
Poh Seng Lee ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Single Phase ◽  
Three Dimensional ◽  
Heat Fluxes ◽  
Experimental Results ◽  
Working Fluid ◽  
Minichannel Heat Exchanger ◽  
Simulation Results ◽  
Good Agreement

Abstract This study investigates the thermal performance of laminar single-phase flow in an additively manufactured minichannel heat exchanger both experimentally and numerically. Distilled water was employed as the working fluid, and the minichannel heat exchanger was made from aluminum alloy (AlSi10Mg) through direct metal laser sintering (DMLS). The minichannel was designed with a hydraulic diameter of 2.86 mm. The Reynolds number ranged from 175 to 1360, and the heat exchanger was tested under two different heat fluxes of 1.5 kWm−2 and 3 kWm−2. A detailed experiment was conducted to obtain the thermal properties of AlSi10Mg. Furthermore, the heat transfer characteristics of the minichannel heat exchanger was analyzed numerically by solving a three-dimensional conjugate heat transfer using the COMSOL Multiphysics® to verify the experimental results. The experimental results were also compared to widely accepted correlations in literature. It is found that 95% and 79% of the experimental data are within ±10% range of both the simulation results and the values from the existing correlations, respectively. Hence, the good agreement found between the experimental and simulation results highlights the possibility of the DMLS technique as a promising method for manufacturing future multiport minichannel heat exchangers.

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