Theoretical Study on Thermal Performance of Trombe Wall Combined with Solar Air Collector

2012 ◽  
Vol 512-515 ◽  
pp. 208-213
Author(s):  
Yu Bie ◽  
Fang Zhou ◽  
Ming Fu Hu ◽  
Qian Peng ◽  
Wen Yuan Mao ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Thermal Performance ◽  
Air Flow ◽  
Flow Channel ◽  
C Programming ◽  
Solar Air Collector ◽  
Trombe Wall ◽  
Collecting Efficiency ◽  
Solar Wall ◽  
The Mathematical Model

A thermal performance mathematical model of Trombe wall combined with solar air collector was established on the base of thermodynamics and fluid dynamics analysis. Then we solved the mathematical model by means of calculating program based on C programming language. The calculating results show the influence law of the area ratio of air opening to air flow channel (Ao/Af ) and the thickness of air flow channel affected on the heat collecting efficiency of solar wall. With the increasing of Ao/Af , the efficiency increases firstly, then increases more slowly, and finally comes to steady. The thickness also affects the efficiency in the same way. Though the results still need a further validation by experiments, they are initially proved correct by the qualitative analysis. The theoretical model can be a tool for the structural optimization of the Trombe wall combined with solar air collector.

scholarly journals Study of Air Flow in A Solar Collector Equipped with Two Inclined Obstacles

2021 ◽  
Vol 321 ◽  
pp. 04015
Author(s):  
Fayssal Benosman ◽  
Mohammed Amine Amraoui
Keyword(s):  
Mathematical Model ◽  
Reynolds Number ◽  
Solar Collector ◽  
Air Flow ◽  
Solar Air Collector ◽  
The Mathematical Model ◽  
Calculation Code

In the present work we have studied the case of a conventional solar air collector and try to see how is it possible to improve it-s efficiency, by changing Reynolds number. Given the complexity of the problem we used the FLUENT calculation code. We made the mathematical model, then we gave a validation of our result by the results of Dimartini, we gave fields of speed, turbulence and a Nusselt profile and factor of friction as a function of the Reynolds Number. The results show that variation of Reynolds number has an influence on the performance of the solar collector, which is why we have used several values in order to observe the most suitable one.

scholarly journals Numerical study of a modified Trombe wall solar collector system

2009 ◽  
Vol 13 (1) ◽  
pp. 195-204 ◽  
Author(s):  
Snezana Dragicevic ◽  
Miroslav Lambic
Keyword(s):  
Mathematical Model ◽  
Numerical Study ◽  
Operational Parameters ◽  
Collector System ◽  
Fast Running ◽  
Simulation Techniques ◽  
Solar Radiation Intensity ◽  
Trombe Wall ◽  
Solar Wall ◽  
The Mathematical Model

The paper presents numerical analysis of efficiency of the modified Trombe wall with forced convection. The analyzed system comprises a double glass glazing, and a massive wall with opening and central channel in it. In order to increase the efficiency, a fan is provided at the bottom vent of the wall. It is more advanced as compared with simple Trombe solar wall with a relatively low thermal resistance, which is taken as a reference in experimental analysis. The mathematical model, composed for the massive solar wall efficiency, is usually very complicated and assessment of the thermal behavior requires the use of thermal simulation techniques. This paper presents steady-state and one-dimensional mathematical model for simplified analysis of thermal efficiency of modified Trombe solar wall. The results from presented model were analyzed to predict the effects of variations in the operational parameters on the solar wall efficiency: solar radiation intensity, air velocity in the entrance duct, and room air temperature. The results have been compared with the available experimental study, and the comparison has shown satisfactory agreement. The obtained results have be used for simple and fast running design tools that designers can use in the early phases of the design process for approximate calculations of efficiency of the passive solar heating systems.

scholarly journals The temperature - insulative material that can work as the insulation and siding and decorative material

2018 ◽  
Vol 245 ◽  
pp. 03018
Author(s):  
Boris Aksenov ◽  
Oleg Stepanov ◽  
ludmila Stefurak
Keyword(s):  
Mathematical Model ◽  
Thermal Performance ◽  
Foam Plastic ◽  
Metallic Layer ◽  
Mechanism Of Formation ◽  
Butt Joints ◽  
Composite Type ◽  
New Material ◽  
Decorative Material ◽  
The Mathematical Model

The article analyzes the new temperature - insulative materials. It is motivated that the temperature - insulative material capable to work in the panel as a temperature insulative and facing-decorative material can be only composite type. The composition of the new material, the technology of its production, as well as the mathematical model of the mechanism of formation of strong crusts at its surfaces. The material that is used for the manufacture of roofing panels, panels BKU with an internal non-metallic layer. These panels allow you to break the bridges of cold in butt joints, which improves thermal performance, reliability and durability of the building as a whole. Based on the developed mathematical model, you can predict the properties of foam plastic.

Air Flow in Yarn Texturing Nozzles

1987 ◽  
Vol 109 (3) ◽  
pp. 197-202 ◽  
Author(s):  
M. Acar ◽  
R. K. Turton ◽  
G. R. Wray
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Experimental Work ◽  
Air Flow ◽  
Air Jet ◽  
Continuous Filament ◽  
The Mathematical Model ◽  
Experimental Nozzle ◽  
Good Agreement

The air-jet texturing process, a purely mechanical means of texturing continuous filament yarns, is described. Industrial texturing nozzles are reviewed and categorized in two groups, either as converging-diverging or cylindrical type nozzles. A mathematical model is developed for the complex airflow in cylindrical type texturing nozzles, and experimental data obtained from various nozzles verify the flow predicted by this model. The mathematical model is also shown to be in good agreement with the data obtained from a modified experimental nozzle, which has a trumpet shaped diverging exit. Further experimental work with a scaled-up model of a typical industrial texturing nozzle is also reported.

Lung-Diaphragm Behavior of the Respiratory System During Input From Excitation

2002 ◽  
Author(s):  
P. Ruby Mawasha ◽  
Paul Lam ◽  
Lalitha Kasturi
Keyword(s):  
Mathematical Model ◽  
Respiratory System ◽  
Periodic Motion ◽  
Constitutive Relations ◽  
Air Flow ◽  
Flow Conditions ◽  
Mouth Pressure ◽  
Parametric Studies ◽  
The Mathematical Model ◽  
Operating Regimes

A numerical behavior of a lung-diaphragm model of a respiratory system during input from mouth pressure and diaphragm excitation is being investigated. A lung-diaphragm is subject to constant inlet air-flow conditions into the respiratory system. The mouth pressure (Macia et. al., 1997) and diaphragm excitation (Ricci et. al., 2002) are described by a constitutive relations containing nonlinearities from rib cage muscles forces and inlet air-flow conditions. Within certain operating regimes, the model exhibits self-excited pulsatile periodic motion and the qualitative features of the response can be understood in terms of the underlying model. Further, the mathematical model is a more general approach and can be used to conduct parametric studies and determine the instability mechanisms involved in the modeling of lung-diaphragm behavior of the respiratory system during input from excitation.

scholarly journals System identification analysis for an air compressor system and enhancement proposal by sensors based in nanostructures

2019 ◽  
Vol 95 ◽  
pp. 02007
Author(s):  
Jesus A. Calderón ◽  
Cesar J. Valdivia ◽  
Roland Mas ◽  
Luis Chirinos ◽  
Enrique Barrantes ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Energy Transfer ◽  
System Identification ◽  
Mechanical System ◽  
Air Flow ◽  
Pressure Level ◽  
Air Pressure ◽  
Air Compressor ◽  
Identification Analysis ◽  
The Mathematical Model

An Air Compressor System is an equipment (mechanical system) which can transmit energy due to increase air pressure level of air flow that through it. This energy can be used in many applications, such as in drills for mining, adding air to tires on vehicles, spraying crops, etc. Therefore, it is necessary to know the mathematical model of an Air Compressor System to study all the thermodynamical variables: “Temperature, Pressure, Air Flow” which let to get a formalized explanation of the energy transfer through this equipment. Furthermore it is described that Air Compressor System can be enhanced while it uses sensors/actuators based in nanostructures.

scholarly journals Experimental Study of Thermal Performance of One-Ended Evacuated Tubes for Producing Hot Air

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Ashish Kumar ◽  
Sanjeev Kumar ◽  
Utkarsh Nagar ◽  
Avadhesh Yadav
Keyword(s):  
Thermal Performance ◽  
Temperature Difference ◽  
Air Flow ◽  
Climatic Conditions ◽  
Working Fluid ◽  
Outlet Temperature ◽  
Flow Rates ◽  
Solar Air Collector ◽  
Evacuated Tubes ◽  
Evacuated Tube

The thermal performance of an evacuated tube solar air collector is experimentally investigated at different air flow rates. Air is used as a working fluid in experimental setup and tested in Indian climatic conditions. The evacuated tube solar air collector consists of fifteen evacuated tubes and manifold channel. The manifold channel consists of a hollow pipe (square pipe) in centre through which air flows. The temperature difference and efficiency are studied with different air flow rates. The reflectors are used to enhance the performance of evacuated tubes solar air collector. It is observed that in case of reflector evacuated tube solar air collector gives higher outlet temperature and temperature difference and has better thermal performance as compared to the case without reflector. The maximum outlet temperature and temperature difference of air are found to be 97.4°C and 74.4°C at a flow rate of 6.70 kg/hr.

scholarly journals Experimental calibration of the mathematical model of Air Torque Position dampers with non-cascading blades

2016 ◽  
Vol 20 (2) ◽  
pp. 567-578
Author(s):  
Sinisa Bikic ◽  
Dusan Uzelac ◽  
Masa Bukurov ◽  
Milivoj Radojcin ◽  
Ivan Pavkov
Keyword(s):  
Mathematical Model ◽  
Air Flow ◽  
Operating Conditions ◽  
Air Velocity ◽  
Experimental Calibration ◽  
Laboratory Facility ◽  
Different Types ◽  
The Moment ◽  
Air Conditioning Systems ◽  
The Mathematical Model

This paper is focused on the mathematical model of the Air Torque Position dampers. The mathematical model establishes a link between the velocity of air in front of the damper, position of the damper blade and the moment acting on the blade caused by the air flow. This research aims to experimentally verify the mathematical model for the damper type with non-cascading blades. Four different types of dampers with non-cascading blades were considered: single blade dampers, dampers with two cross-blades, dampers with two parallel blades and dampers with two blades of which one is a fixed blade in the horizontal position. The case of a damper with a straight pipeline positioned in front of and behind the damper was taken in consideration. Calibration and verification of the mathematical model was conducted experimentally. The experiment was conducted on the laboratory facility for testing dampers used for regulation of the air flow rate in heating, ventilation and air conditioning systems. The design and setup of the laboratory facility, as well as construction, adjustment and calibration of the laboratory damper are presented in this paper. The mathematical model was calibrated by using one set of data, while the verification of the mathematical model was conducted by using the second set of data. The mathematical model was successfully validated and it can be used for accurate measurement of the air velocity on dampers with non-cascading blades under different operating conditions.

The Ventilation and Thermal Performance of the Patio Space in Shanghai Shikumen House

2013 ◽  
Vol 742 ◽  
pp. 8-12
Author(s):  
Xiao Yu Luo ◽  
Jian Ge ◽  
Yi Cai
Keyword(s):  
Mathematical Model ◽  
Thermal Performance ◽  
Simulation Analysis ◽  
Thermal Environment ◽  
Three Dimensional ◽  
Simulation Software ◽  
Wind Environment ◽  
Residential Architecture ◽  
Dimensional Simulation ◽  
The Mathematical Model

Shanghai Shikumen house is a typical one of Chinese traditional residential architecture, which has a "two patios & one corridor" pattern adapting to the climate of Shanghai. In existing researches, most study of the thermal performance dwelling with courtyard is still qualitative. This research constructed the quantitative simulation of the " two patios & one corridor" pattern in Shanghai Shikumen house based on the mathematical model by the technical simulation software, and compared the above mode with the general courtyard house to test the advances of it. First of all, the research conduct a three-dimensional simulation analysis on the "two patios & one corridor" pattern and the general "Two patios" pattern. Then we compared the results of the wind environment of the two modes and found the "two patios & one corridor" mode has advances on ventilation. Secondly, we did thermal environment simulations of the rooms in the above two modes, and compared the analysis results of two modes. We found that the "two patios & one corridor" pattern did better in the room thermal. Finally, we hope this research can provide certain reference for the design of the sustainable residential architecture.

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