Effect of the Circulation Number on the Stratification Coefficient for Solar Heating Systems

1991 ◽  
Vol 113 (4) ◽  
pp. 250-256
Author(s):  
Rajesh N. Dave
Keyword(s):  
Numerical Simulations ◽  
Analytical Model ◽  
General Expression ◽  
Entire Range ◽  
Solar Heating ◽  
Previous Model ◽  
Heating Systems ◽  
A Value ◽  
Air Heating ◽  
Definition Of

The effect of the circulation number (the number of times the entire storage mass is circulated through the system each day) on the stratification coefficient is investigated. An earlier model ignored the effect of the circulation number, assuming that a large value (a value > 2) did not have any effect. In this paper, an analytical model is developed to consider the effect of low circulation number. This model is combined with the previous model and a general expression for the stratification coefficient is developed that is valid for the entire range of circulation number. The extended analytical model is verified through numerical simulations. The results are valid for liquid-based as well as air heating systems. Clarifications are made regarding the definition of the stratification coefficient by introducing a concept of an instantaneous stratification coefficient.

scholarly journals Airflow mixing augmentation device for hot-air heating systems in modular boilers

2016 ◽  
Vol 92 ◽  
pp. 01049
Author(s):  
Nikolay I. Kurilenko ◽  
Pavel A. Artamonov ◽  
Elena Yu. Kurilenko ◽  
Gennady Ya. Mamontov
Keyword(s):  
Heating Systems ◽  
Hot Air ◽  
Air Heating

Generating application design data for solar air heating systems

Solar Energy ◽  
1980 ◽  
Vol 25 (6) ◽  
pp. 527-530 ◽  
Author(s):  
T.A. Reddy ◽  
C.L. Gupta
Keyword(s):  
Design Data ◽  
Heating Systems ◽  
Air Heating ◽  
Application Design

The effects of geometric offsets on the dynamic responses of a Scott—Russell amplifying mechanism with flexible hinges

2009 ◽  
Vol 223 (10) ◽  
pp. 2413-2423 ◽  
Author(s):  
C-M Chen ◽  
R-F Fung
Keyword(s):  
Numerical Simulations ◽  
Analytical Model ◽  
Dynamic Responses ◽  
Analytical Models ◽  
Dynamic Equations ◽  
Magnification Factor ◽  
Flexure Hinges ◽  
Magnification Factors ◽  
Straight Line ◽  
Deviation Factor

The dynamic equations of a micro-positioning Scott—Russell (SR) mechanism associated with two flexible hinges and an offset are developed to calculate output responses. Both rigid and flexible hinges are considered to explore the results. The main features in the kinematics of the SR mechanism are its displacement amplification and straight-line motion, which are widely needed in practical industries. The manufacturing inaccuracy of the SR mechanism definitely causes geometric offsets of flexure hinges, and affects displacement amplification and straight-line output motion. Analytical models based on kinematics and Hamilton's principle are derived to explore the variation of linearity ratio, magnification factor, and deviation factor due to various offsets and link lengths. From numerical simulations for the SR mechanism with various offsets of flexible hinges in the conditions of different link lengths, it is found that offsets of flexure hinges obviously affect the amplifying factor and linearity ratio, and appear to dominate the changes of magnification factors. Moreover, an analytical model is also used to predict magnification factors due to various offsets. Finally, some conclusions concerning the effects of offset on the performance of the SR mechanism are drawn.

The optimization of solar heating systems

Solar Energy ◽  
1981 ◽  
Vol 26 (4) ◽  
pp. 375-376 ◽  
Author(s):  
Paul R. Barnes
Keyword(s):  
Solar Heating ◽  
Heating Systems

scholarly journals Electromagnetic Shielding Effectiveness of Woven Fabrics with High Electrical Conductivity: Complete Derivation and Verification of Analytical Model

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1657 ◽  
Author(s):  
Marek Neruda ◽  
Lukas Vojtech
Keyword(s):  
Electrical Conductivity ◽  
Analytical Model ◽  
Electromagnetic Interference ◽  
Woven Fabrics ◽  
Electromagnetic Shielding ◽  
High Electrical Conductivity ◽  
Shielding Effectiveness ◽  
Textile Composite ◽  
A Value ◽  
Electromagnetic Shielding Effectiveness

In this paper, electromagnetic shielding effectiveness of woven fabrics with high electrical conductivity is investigated. Electromagnetic interference-shielding woven-textile composite materials were developed from a highly electrically conductive blend of polyester and the coated yarns of Au on a polyamide base. A complete analytical model of the electromagnetic shielding effectiveness of the materials with apertures is derived in detail, including foil, material with one aperture, and material with multiple apertures (fabrics). The derived analytical model is compared for fabrics with measurement of real samples. The key finding of the research is that the presented analytical model expands the shielding theory and is valid for woven fabrics manufactured from mixed and coated yarns with a value of electrical conductivity equal to and/or higher than σ = 244 S/m and an excellent electromagnetic shielding effectiveness value of 25–50 dB at 0.03–1.5 GHz, which makes it a promising candidate for application in electromagnetic interference (EMI) shielding.

Energetic performances of an optimized passive Solar Heating Prototype used for Tunisian buildings air-heating application

2014 ◽  
Vol 87 ◽  
pp. 285-296 ◽  
Author(s):  
Farah Mehdaoui ◽  
Majdi Hazami ◽  
Nabiha Naili ◽  
Abdelhamid Farhat
Keyword(s):  
Solar Heating ◽  
Air Heating ◽  
Passive Solar
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