scholarly journals TEMPERATURE DISTRIBUTION WITHIN THE RISING PIPE IN FLAT PLATE SOLAR COLLECTOR

2021 ◽  
Vol 25 (5) ◽  
pp. 56-66
Author(s):  
Mohammed H. Alkhafaji ◽  
◽  
Basim H. Abood ◽  
Mohammed H. Alhamdo ◽  
◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Cross Section ◽  
Experimental Tests ◽  
Traditional Model ◽  
Ansys Fluent ◽  
Absorption Area ◽  
Section Model ◽  
The Difference ◽  
Flat Plate Solar Collector ◽  
Experimental Findings

In the present study, the effect of increasing absorption area by using two different cross-section shapes of rising pipe namely semi-circle cross-section (model -A-) and elliptic cross-section (model -B-) on the temperature distribution of operating liquid within rising pipe of the FPSC is studied numerically and experimentally. Experimental tests are conducted under weather Baghdad – Iraq, while the numerical results are obtained by using Ansys Fluent CFD. The difference between the experimental findings and numerical findings for the average temperature of the water in the tank and the temperature of the operating liquid at exit rising pipe is 8.12 % and 8.36 % respectively. The results have shown that the temperature distribution for all new models higher than the traditional model. Furthermore, model -B- has higher other models under study. Hence, the best model according to the current study is model -B- increase by (2.4%), (2.2%) and (2.5%) regarding the temperature of the operating liquid at the inlet, center, and outlet respectively compared to the traditional model.

INFLUENCE THE RIBS IN NEW MODEL OF CHANNEL PATH ON HYDRO-THERMAL PERFORMANCE IN SERPENTINE MINI- CHANNEL HEAT SINK

2021 ◽  
Vol 25 (Special) ◽  
pp. 2-115-2-123
Author(s):  
Hind M. Mohammed ◽  
◽  
Basim H. Abood ◽  
Keyword(s):  
Heat Transfer ◽  
Heat Sink ◽  
Traditional Model ◽  
Conventional Model ◽  
Ansys Fluent ◽  
Well Model ◽  
New Models ◽  
Overall Performance ◽  
The Difference ◽  
Good Agreement

The aim of the present study is to enhance of heat transfer in mini channel heat sink. To reach the target of this study a new models of mini channel heat sink is proposed the traditional model, model (A) and model (B). Both model (A, B) has straight serpentine mini channel heat sink with inlet at the center, the difference between them is that model(B) has ribs within channel, the diameter of ribs is 1 mm with distance between ribs 5mm. A 3D (ANSYS Fluent program) 2019R3 is used to obtain the numerical outcomes. A good agreement is found when compared the experimental outcomes from the literature review and the numerical results of the traditional model in the current study. Furthermore, the findings demonstrate that the formation of flow has a great impact on heat transfer, Though the model with serpentine straight channel improve the pressure drop, thermal resistance, Nusselt number and the distribution of temperature in the base of heat sink. The overall performance factor (OPF) for new models under study are superior than conventional model. In addition, the average OPF for model (A) is [1.43] and for model (B) is [1.33] as compared with traditional model. As well, model (A) is superior as compared with model (B) by 6.99 % due to the effectual uniformity in the base of heat sink and efficient OPF.

The Feeling Brain — The Thinking Soul

Human Affairs ◽  
2010 ◽  
Vol 20 (3) ◽  
Author(s):  
Silvia Gáliková
Keyword(s):  
Clinical Practice ◽  
New Technologies ◽  
Emotional Responses ◽  
Traditional Model ◽  
Emotional States ◽  
Emotional Life ◽  
Recent Advances ◽  
The Difference ◽  
Experimental Findings

The Feeling Brain — The Thinking SoulRecent advances in neuroscience have dramatically improved our understanding of human emotional states. With the help of new technologies and models, scholars are beginning to unravel the "mystery" of emotional life. Confusions in contemporary emotion studies are due to the traditional model of a person as a rational conscious agent. The paper highlights two problematic aspects of this prevailing model: the relation between emotion and reason and the relation between emotion and consciousness. Firstly, it is claimed that the difference between emotions and thoughts does not transcend their mutual interconnectivity. Secondly, conscious content and emotional responses are both products of specialized emotion systems that operate unconsciously. Both claims are supported by experimental findings and clinical practice.

Thermal calculation of submersible motors

2020 ◽  
Author(s):  
R.R. Gizatullin ◽  
S.N. Pescherenko ◽  
A.V. Shiverskiy
Keyword(s):  
Temperature Distribution ◽  
Cross Section ◽  
Annular Channel ◽  
Thermal Calculation ◽  
Ansys Fluent ◽  
Coefficient Of Thermal Conductivity ◽  
The Cross ◽  
Prandtl Numbers ◽  
Solid Liquid Interface ◽  
Solid Liquid

The paper proposes a method of thermal calculation of submersible electric motors intended for use at the stage of their conceptual design. The model is based on the complete system of hydrodynamic equations averaged over the motor cross section and the annular channel through which coolant is pumped. All geometric dimensions and properties of the substance are set. The temperature distribution over the cross section and along the length of the motor is calculated. Two approximations are used. In the first one, the temperature distribution in the cross section of the electric motor was averaged over the corners, which requires setting an effective coefficient of thermal conductivity inside the stator grooves filled with winding wires and electrical insulation. In the second approximation, the heat transfer at the solid – liquid interface was specified through the empirical dependence of the Nusselt number on the Reynolds and Prandtl numbers. To verify the model, the results obtained were compared with calculations by the method of computational fluid dynamics in the ANSYS Fluent software package. The error in calculating the insulation temperature was not more than 5%.

Numerical Investigation to Evaluate the Performance of Helical Coiled Tube Heat Exchanger With and Without Nanofluid

2013 ◽  
Author(s):  
Qasim Saleh Mahdi ◽  
Sahar A. Fattah ◽  
Firas Jumia
Keyword(s):  
Heat Exchanger ◽  
Temperature Distribution ◽  
Flow Pattern ◽  
Helical Coil ◽  
Ansys Fluent ◽  
Numerical Work ◽  
Tube Heat Exchanger ◽  
The Difference ◽  
Coil Heat Exchanger ◽  
20 Nm

A numerical analysis presented out to simulate internal forced convection and temperature distribution in helical coil tube with and without nanofluid. An ANSYS FLUENT package 14.1 commercial copy with SOLID WORK and GAMBIT software program is employed. The flow pattern and temperature distribution in helical coil tube heat exchanger is studied with and without nanofluid. Numerical work included two parts: the first is included helical coil heat exchanger with optimum curvature ratio (17). An optimum helical coil pitch has been used to study the temperature distribution and flow pattern difference along the turns without nanofluid. The second part included studying the effect of using (Oxide Titanium TiO2) nanoparticle powder with 20 nm diameter dispersed in distilled water with 0.6 % volume concentrations on the same above variables. Temperature contours showed that the temperature decreased along the coil. Also there is difference in temperature between turns. After turn nine the difference become less. The results showed enhancement in the heat flow for fluid with nanofluid compared to without nanofluid.

Numerical and Experimental Evaluation of the Temperature Distribution Within Laminated Veneer Lumber (LVL) Exposed to Fire

2010 ◽  
Vol 1 (3) ◽  
pp. 145-159 ◽  
Author(s):  
Massimo Fragiacomo ◽  
Agnese Menis ◽  
Peter Moss ◽  
Andrew Buchanan ◽  
Isaia Clemente
Keyword(s):  
Temperature Distribution ◽  
Cross Section ◽  
Cross Sections ◽  
Structural Design ◽  
Experimental Tests ◽  
Radiata Pine ◽  
Complex Problem ◽  
Laminated Veneer Lumber ◽  
Timber Member ◽  
The University

The fire resistance evaluation of a timber member is an important and complex problem of structural design. In order to solve this problem, it is crucial to have reliable information on the temperature distribution within a timber cross-section exposed to fire, and to develop a numerical model for the prediction of such a quantity. The paper reports the experimental-numerical comparisons in terms of temperature distribution within a timber member made from radiata pine LVL (laminated veneer lumber) exposed to fire. The experimental tests were performed at the University of Canterbury and BRANZ (New Zealand) on 146×60, 300×105 and 360×133 mm LVL members. The temperature distribution was monitored using several thermocouples. The numerical results were obtained using the Abaqus FE code with different conductive models. The Eurocode 5 and Frangi's proposals led to similar results characterized by acceptable approximation close to the surface. Since the accuracy reduced for deeper fibres, a new proposal based on a different variation of the conductivity with the temperature was made. The proposal led to acceptable approximation throughout the tested cross-sections.

Automatic Tread Gaging Machine

1979 ◽  
Vol 7 (1) ◽  
pp. 31-39
Author(s):  
G. S. Ludwig ◽  
F. C. Brenner
Keyword(s):  
Experimental Tests ◽  
Automatic Machine ◽  
Wear Rates ◽  
Handling Device ◽  
Straight Line ◽  
Component Systems ◽  
Before And After ◽  
Good Repeatability ◽  
The Difference ◽  
Straight Lines

Abstract An automatic tread gaging machine has been developed. It consists of three component systems: (1) a laser gaging head, (2) a tire handling device, and (3) a computer that controls the movement of the tire handling machine, processes the data, and computes the least-squares straight line from which a wear rate may be estimated. Experimental tests show that the machine has good repeatability. In comparisons with measurements obtained by a hand gage, the automatic machine gives smaller average groove depths. The difference before and after a period of wear for both methods of measurement are the same. Wear rates estimated from the slopes of straight lines fitted to both sets of data are not significantly different.

scholarly journals The Chosen Aspects of Skew Rolling of Hollow Stepped Shafts

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 764
Author(s):  
Jarosław Bartnicki ◽  
Yingxiang Xia ◽  
Xuedao Shu
Keyword(s):  
Cross Section ◽  
Rolling Mill ◽  
Metal Flow ◽  
Experimental Tests ◽  
Rolling Process ◽  
Numerical Control ◽  
Technological Parameters ◽  
Flow Mechanisms ◽  
The Individual ◽  
Skew Rolling

The paper presents chosen aspects of the skew rolling process of hollow stepped products with the use of a skew rolling mill designed and manufactured at the Lublin University of Technology. This machine is characterized by the numerical control of spacing between the working rolls and the sequence of the gripper axial movement, which allows for the individual programming of the obtained shapes of parts such as stepped axles and shafts. The length of these zones and the values of possibly realizable cross-section reduction and obtained outlines are the subject of this research paper. The chosen results regarding the influence of the technological parameters used on the course of the process are shown in the present study. Numerical modelling using the finite element method in Simufact Forming, as well as the results of experimental tests performed in a skew rolling mill, were applied in the conducted research. The work takes into account the influence of cross-section reduction of the hollow parts and the feed rate per rotation on the metal flow mechanisms in the skew rolling process. The presented results concern the obtained dimensional deviations and changes in the wall thickness determining the proper choice of technological parameters for hollow parts formed by the skew rolling method. Knowledge about the cause of the occurrence of these limitations is very important for the development of this technology and the choice of the process parameters.

scholarly journals Apical Extrusion of Debris Produced during Continuous Rotating and Reciprocating Motion

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Giselle Nevares ◽  
Felipe Xavier ◽  
Luciana Gominho ◽  
Flávia Cavalcanti ◽  
Marcely Cassimiro ◽  
...  
Keyword(s):  
Cross Section ◽  
Sodium Hypochlorite ◽  
Reciprocating Motion ◽  
Continuous Motion ◽  
Analytical Balance ◽  
Root Canals ◽  
Apical Extrusion ◽  
Final Weight ◽  
The Difference

This study aimed to analyse and compare apical extrusion of debris in canals instrumented with systems used in reciprocating and continuous motion. Sixty mandibular premolars were randomly divided into 3 groups (n=20): the Reciproc (REC), WaveOne (WO), and HyFlex CM (HYF) groups. One Eppendorf tube per tooth was weighed in advance on an analytical balance. The root canals were instrumented according to the manufacturer’s instructions, and standardised irrigation with 2.5% sodium hypochlorite was performed to a total volume of 9 mL. After instrumentation, the teeth were removed from the Eppendorf tubes and incubated at 37°C for 15 days to evaporate the liquid. The tubes were weighed again, and the difference between the initial and final weight was calculated to determine the weight of the debris. The data were statistically analysed using the Shapiro-Wilk, Wilcoxon, and Mann-Whitney tests (α=5%). All systems resulted in the apical extrusion of debris. Reciproc produced significantly more debris than WaveOne (p<0.05), and both systems produced a greater apical extrusion of debris than HyFlex CM (p<0.001). Cross section and motion influenced the results, despite tip standardization.

scholarly journals Experimental Evidence of Specimen-Size Effects on EN-AW6082 Aluminum Alloy in VHCF Regime

2021 ◽  
Vol 11 (9) ◽  
pp. 4272
Author(s):  
Stefano Invernizzi ◽  
Francesco Montagnoli ◽  
Alberto Carpinteri
Keyword(s):  
Aluminium Alloy ◽  
Cross Section ◽  
Fatigue Testing ◽  
Testing Machine ◽  
Experimental Tests ◽  
Theoretical Explanation ◽  
Specimen Size ◽  
Section Surface ◽  
Middle Cross Section ◽  
Ultrasonic Fatigue

The present paper investigates the influence of the specimen size of EN-AW6082 wrought aluminium alloy subjected to very high cycle fatigue (VHCF) tests. The hourglass specimens were tested under fully reversed loading condition, up to 109 cycles, by means of the ultrasonic fatigue testing machine developed by Italsigma® (Italy). Three specimens groups were considered, with a diameter in the middle cross-section ranging from 3 mm up to 12 mm. The stress field in the specimens was determined numerically and by strain gauge measurements in correspondence of the cross-section surface. The dispersion of experimental results has been accounted for, and data are reported in P-S-N diagrams. The decrease in fatigue resistance with increasing specimen size is evident. Theoretical explanation for the observed specimen-size effect is provided, based on Fractal Geometry concepts, allowing to obtain scale independent P-S*-N curves. The fatigue life expectation in the VHCF regime of the EN-AW6082 aluminium alloy full-scale components is rather overestimated if it is assessed only from standard small specimens of 3 mm in diameter. Experimental tests carried out on larger specimens, and a proper extrapolation, are required to assure safe structural design.

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