scholarly journals Numerical Simulation Investigation of a Double Skin Transpired Solar Air Collector

2022 ◽  
Vol 12 (1) ◽  
pp. 520
Author(s):  
Charles Berville ◽  
Florin Bode ◽  
Cristiana Croitoru
Keyword(s):  
Numerical Simulation ◽  
Solar Collector ◽  
Ambient Air ◽  
Point Of View ◽  
Airflow Rate ◽  
Solar Collectors ◽  
A Value ◽  
Double Skin ◽  
Separation Plate ◽  
Guide Values

Transpired solar collectors (TSC) are one of the most popular solar thermal technologies for building façades. TSC use solar energy to heat the absorber surface, which transmits thermal energy to the ambient air. A variant of TSC, namely, a double skin transpired solar collector (DSTSC), has been analyzed in this paper, thus providing guide values and a technical point of view for engineers, architects, and constructors when designing such transpired solar collectors. Three important parameters were addressed in this study through numerical simulation: the influence of a separation plate introduced in a TSC, turning it into a DSTSC; the air layer thickness influence on the performance of the collector; and the influence of the used absorber materials for the separation plate material. Greater heat exchange efficiency was noticed for the DSTSC at every imposed airflow rate compared with the TSC. Regarding the thickness of the collector, the efficiency gradually increased when increasing the solar collector thickness until it reached a value of 20 cm, though not varying significantly at a thickness of 30 cm.

A Numerical Model for Thermal Performance of an Unglazed Transpired Solar Collector

2011 ◽  
Author(s):  
Saeed Moaveni ◽  
Patrick A. Tebbe ◽  
Louis Schwartzkopf ◽  
Joseph Dobmeier ◽  
Joseph Gehrke ◽  
...  
Keyword(s):  
Numerical Model ◽  
Air Temperature ◽  
Thermal Performance ◽  
Solar Collector ◽  
Energy Savings ◽  
Ambient Air ◽  
Solar Collectors ◽  
Heating Unit ◽  
Plate Temperature ◽  
Building Wall

In this paper, we will present a numerical model for estimating the thermal performance of unglazed transpired solar collectors located on the Breck School campus in Minneapolis, Minnesota. The solar collectors are installed adjacent to the southeast facing wall of a field house. The collectors preheat the intake air before entering the primary heating unit. The solar collector consists of 8 separate panels (absorber plates). Four fans are connected to the plenum that is created by the absorber plates and the adjoining field house wall. All fresh air for the field house is provided by the solar collectors before being filtered and heated by four, independent two stage natural gas fired heaters. Moreover, the following data were collected onsite using a data acquisition system: indoor field house space temperature, ambient air temperature, wind speed, wind direction, the plenum exit air temperature, the absorber plate temperature, and the air temperatures inside the plenum. The energy balance equations for the collector, the adjacent building wall, and the plenum are formulated. The numerical model is used to predict the air temperature rise inside the plenum, recaptured heat loss from the adjoining building wall, energy savings, and the efficiency of the collectors. The results of the numerical model are then compared to the results obtained from the onsite measurements; which are in good agreement. The model presented in this paper is simple yet accurate enough for architects and engineers to use it with ease to predict the thermal performance of a collector.

scholarly journals Three-Dimensional Numerical Simulation of a Flat Plate Solar Collector with Double Paths

2021 ◽  
Vol 39 (4) ◽  
pp. 1087-1096
Author(s):  
Mohammed Amine Amraoui
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Solar Collector ◽  
Three Dimensional ◽  
Heat Transfer Fluid ◽  
Minimal Cost ◽  
Solar Collectors ◽  
Flat Plate Solar Collector ◽  
Exchange Surface ◽  
Calculation Code

Flat air solar collectors are used for heat transfer between the absorber and the heat transfer fluid, to improve this transfer there are several methods. Among these methods, the exchange surface lengthening and the creation of turbulence. In this work is done to give a comparison between two types of solar collectors, so we have made an improvement of Ben Slama Romdhane's solar collector by creating two air flow passages to increase heat transfer. We made a 3D simulation of a flat air solar collector with transverse baffles which causes turbulence and increases the exchange surface; we use the ANSYS calculation code to make the simulation and gives results with a brief time and minimal cost.

Evaluation Of The Functional Of Space-Planning Arrangement Of A Building

2019 ◽  
pp. 4-9
Keyword(s):  
Numerical Simulation ◽  
Life Cycle ◽  
Initial Data ◽  
Objective Assessment ◽  
Objective Evaluation ◽  
Point Of View ◽  
Shopping Centers ◽  
Space Planning ◽  
Planning Decisions ◽  
The Cost

The article focuses on the problem of the lack of objective evaluation of space-planning arrangement of buildings as a creative approach of the architect to the performing of functional tasks by the object. It is proposed to create a methodology for assessing the functional of space-planning solutions of buildings on the basis of numerical simulation of functional processes using the theory of human flows. There is a description of the prospects of using this method, which makes it possible to increase the coefficient of compactness, materials and works saving, more efficient use of space, reduce the cost of the life cycle of the building, save human forces and time to implement the functional of the building. The necessary initial data for modeling on the example of shopping and shopping-entertainment centers are considered. There are three main tasks for algorithmization of the functional of shopping centers. The conclusion is made about necessity of development of a method for objective assessment of buildings from the point of view of ergonomics of space-planning decisions based on the study of human behavior in buildings of different purposes.

The Control of the Eye's Intrinsic Muscles: A Multivariable Optimum Performance Control System

1968 ◽  
Vol 1 (8) ◽  
pp. T.129-T.132 ◽  
Author(s):  
F. M. Toates
Keyword(s):  
Control System ◽  
Control Systems ◽  
Pupil Diameter ◽  
Control Model ◽  
Point Of View ◽  
Theoretical Point ◽  
Pupil Control ◽  
Performance Control ◽  
A Value ◽  
Intrinsic Muscles

The reciprocal interaction between the accommodation and pupil control systems of the human eye is examined from a theoretical point of view. The system, which is responsible for maintaining pupil diameter at a value which is a compromise between conflicting requirements, is represented by a control model, and is considered in terms of the concept of a performance index.

Adoption of nanofluids in low-enthalpy parabolic trough solar collectors: Numerical simulation of the yearly yield

2016 ◽  
Vol 118 ◽  
pp. 306-319 ◽  
Author(s):  
Gianluca Coccia ◽  
Giovanni Di Nicola ◽  
Laura Colla ◽  
Laura Fedele ◽  
Mauro Scattolini
Keyword(s):  
Numerical Simulation ◽  
Solar Collectors ◽  
Parabolic Trough

scholarly journals Dynamic Integrated Model for Assessing Fisheries: Discard Bans as an Implicit Value-Added Tax

2021 ◽  
Author(s):  
Jose Maria Da Rocha ◽  
Javier García-Cutrín ◽  
Maria-Jose Gutiérrez ◽  
Raul Prellezo ◽  
Eduardo Sanchez
Keyword(s):  
Value Added ◽  
Point Of View ◽  
Value Added Tax ◽  
Biological Variables ◽  
A Value ◽  
Long Run ◽  
The Social ◽  
Negative Effect ◽  
Short Run ◽  
The Impact

AbstractIntegrated economic models have become popular for assessing climate change. In this paper we show how these methods can be used to assess the impact of a discard ban in a fishery. We state that a discard ban can be understood as a confiscatory tax equivalent to a value-added tax. Under this framework, we show that a discard ban improves the sustainability of the fishery in the short run and increases economic welfare in the long run. In particular, we show that consumption, capital and wages show an initial decrease just after the implementation of the discard ban then recover after some periods to reach their steady-sate values, which are 16–20% higher than the initial values, depending on the valuation of the landed discards. The discard ban also improves biological variables, increasing landings by 14% and reducing discards by 29% on the initial figures. These patterns highlight the two channels through which discard bans affect a fishery: the tax channel, which shows that the confiscation of landed discards reduces the incentive to invest in the fishery; and the productivity channel, which increases the abundance of the stock. Thus, during the first few years after the implementation of a discard ban, the negative effect from the tax channel dominates the positive effect from the productivity channel, because the stock needs time to recover. Once stock abundance improves, the productivity channel dominates the tax channel and the economic variables rise above their initial levels. Our results also show that a landed discards valorisation policy is optimal from the social welfare point of view provided that incentives to increase discards are not created.

Optimizing Skyscrapers' Spatial Integrated DSF-MTMD System Under Wind Loads

2019 ◽  
Author(s):  
Oren Lavan ◽  
Liran Anaby
Keyword(s):  
Structural Engineering ◽  
Tall Buildings ◽  
Point Of View ◽  
Wind Loads ◽  
Optimization Approach ◽  
Wind Effects ◽  
Mass Damper ◽  
Double Skin ◽  
The Cost ◽  
Formal Optimization

<p>From a structural engineering point of view, wind effects pose one of the major challenges to tall buildings. From a performance/architectural point of view, climatologic aspects pose a major challenge. Remedies for each challenge separately have been proposed. One of the remedies for wind effects is the Tunes-Mass-Damper (TMD) or multiple TMD's. To mitigate climatological issues, the Double-Skin-Façade (DSF) has been developed. Recently it has been suggested to take advantage of the space between the two skins of the DSF system to allocate TMD's.</p><p>In this work, another step is taken towards a single remedy for both challenges. A modified version of the TMD-DSF system proposed by Moon (2016) is presented. That is, parts of the mass of the DSF envelope itself are used as part of a multiple TMD (MTMD) system. This is obtained by connecting these parts to the building using springs and dampers while allowing the DSF to move parallel to the floor edges. Furthermore, the DSF-MTMD system is optimized using a formal optimization approach. The optimization indicates which parts of the envelope should be connected to the building rigidly and which should be used as TMD's. Furthermore, the properties of the springs and the dampers are determined by minimizing the cost associated with transforming the DSF system to a DSF-MTMD system and limiting wind responses to desired values.</p>

STOCHASTIC RESONANCE IN CHUA’S CIRCUIT DRIVEN BY AMPLITUDE OR FREQUENCY MODULATED SIGNALS

1994 ◽  
Vol 04 (02) ◽  
pp. 441-446 ◽  
Author(s):  
V.S. ANISHCHENKO ◽  
M.A. SAFONOVA ◽  
L.O. CHUA
Keyword(s):  
Numerical Simulation ◽  
Stochastic Resonance ◽  
Signal To Noise Ratio ◽  
Point Of View ◽  
Chua’S Circuit ◽  
Signal Distortion ◽  
Signal To Noise ◽  
Chua's Circuit ◽  
Noise Ratio ◽  
Modulated Signals

Using numerical simulation, we establish the possibility of realizing the stochastic resonance (SR) phenomenon in Chua’s circuit when it is excited by either an amplitude-modulated or a frequency-modulated signal. It is shown that the application of a frequency-modulated signal to a Chua’s circuit operating in a regime of dynamical intermittency is preferable over an amplitude-modulated signal from the point of view of minimizing the signal distortion and maximizing the signal-to-noise ratio (SNR).

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