scholarly journals Prediction and comparison of size of the copper and aluminium bus duct system based on ampacity and temperature variations using MATLAB

2018 ◽  
Vol 22 (2) ◽  
pp. 1049-1057
Author(s):  
S. Thirumurugaveerakumar ◽  
M. Sakthivel ◽  
Deve Sharmila
Keyword(s):  
Temperature Variation ◽  
Forced Convection ◽  
Algebraic Equation ◽  
Temperature Rise ◽  
Thermal Model ◽  
Cooling Mode ◽  
Standard Size ◽  
The Cost ◽  
Forced Cooling ◽  
Allowable Temperature

The main objective of this paper is to propose an algorithm to predict and compare the sizes of the bus bar with materials like copper and aluminum by considering the allowable ampacity and allowable temperature rise with natural and forced convection cooling arrangement. Theoretical analysis is carried out with modified size of the copper bus bar using MATLAB, to analyze the ampacity and temperature variation under the natural and forced convection mode. The algebraic equation developed from thermal model is solved using MATLAB for the determination of the allowable temperature rise and ampacity of rectangular-section bus bars of copper and aluminum and also for different sizes of bus bar. An algorithm has been developed for the analysis. Experimental observations of temperature variation in copper bus bar with standard size under natural and forced cooling mode are validated with the algebraic equation developed from thermal model is solved using MATLAB. It is concluded that bus bar dimensions are compared for the materials copper and aluminum to predict the suitable equivalent dimensions for the same ampacity level and within the allowable temperature rise to reduce the cost of panel.

scholarly journals Problem Faced by Precast Industry to Implement in Residential Construction

2020 ◽  
Vol 9 (5) ◽  
pp. 2394-2396
Keyword(s):  
Residential Construction ◽  
Joint Stability ◽  
Standard Size ◽  
Research Survey ◽  
Technical Issues ◽  
Storage Area ◽  
Standard Rate ◽  
The Cost ◽  
Cost Of Construction

The Precast industry is booming industry now a day, but then also the implementation ratio of precast member in residential construction work is not up to the mark. As we all know that precast having numerous advantages over the cast in situ construction method, for example it saves the total time of construction which indirectly reduces the cost of construction but still we are lagging behind in implementation of precast in it. In this research we have listed out some problem which can be cause of less implementation of precast in residential construction buildings. As discussed in paper, there are so many factors are affected on Implementation of Precast in Residential Construction Sector For example: Technical Issues and General Issues. In Technical Issues Joint stability problem during Erection, Standard size of precast element, Leakage Issues, Design change related problem, Requirement of Standard Rate per Panel, End user Profit, Additional Taxes, General Issues are: Transportation of Precast Element, Loading and Unloading problems, Transportation to sight, Storage Area, Skilled Labour Research has done and data is collected through Questionery survey, Field survey, and research survey.

Constructal Theory of the Minimum Requirements for Forced Convection Cooling Solutions

2005 ◽  
Author(s):  
E. J. Walsh ◽  
R. Grimes
Keyword(s):  
Forced Convection ◽  
Constructal Theory ◽  
Short Paper ◽  
The Past ◽  
Minimum Requirements ◽  
Convection Cooling ◽  
Cooling Technology ◽  
Level Of Understanding ◽  
Forced Cooling ◽  
Minimum Velocity

The advances in microfluidics and microelectronics bring with them the need to provide new cooling solutions for many applications. A number of technologies are under development for forced convection cooling at the microscale. This short paper, through the new constructal theory of Bejan, presents the minimum velocity requirements of any such technology to be truly useful in a new design. Thus the theory presented in this paper, should form the first step in the design process of any new forced cooling technology for mini-micro scale applications. Furthermore, it is demonstrated that the use of the constructal theory provides a heightened level of understanding to the problem of forced convection, while simultaneously deriving the empirical correlations proposed in the literature over the past number of decades.

scholarly journals Use of Variators in Applying the Cost Calculation Methodology in Small and Medium Furniture Enterprises Based on Changes in Human Body Dimensions

2019 ◽  
Vol 70 (1) ◽  
pp. 27-35 ◽  
Author(s):  
Marek Potkány ◽  
Miloš Hitka ◽  
Silvia Lorincová ◽  
Lucia Krajčírová ◽  
Peter Štarchoň
Keyword(s):  
Human Body ◽  
Value Chain ◽  
Adult Population ◽  
Cost Calculation ◽  
Anthropometric Measures ◽  
Standard Size ◽  
Body Dimensions ◽  
A Value ◽  
Calculation Methodology ◽  
The Cost

Based on the research of anthropometric measures of Slovak adult population, it can be observed that during the last 25 years, anthropometric data have been rising by about 4.5-5 % in most analysed characters. As data on human body dimensions changes, the requirements for material consumption and production time, expressed by the rate of labour cost, are changing. In this context, sustainable profitability of the company can be achieved through each segment of a value chain. One of these segments is the product and its price, which is based on costs allocated in the system of full or variable costing. As the value of quantiles characteristics of anthropometric characters was used to create ergonomic, health and construction norms and standards in the furniture industry, it is necessary to review the adequacy of existing standard-size single bed. Since the dimensions of single bed are standardised, 200 cm x 90 cm or 200 cm x 100 cm, it is clear that due to the secular trend of anthropometric measure of a man, the dimensions are currently inadequate. This paper presents the use of variators when applying the most commonly used absorption costing in small and medium furniture enterprises. It shows the costs involved, when the input parameters are changed.

Dry Machining of Brass Using Titanium Carbonitride (TiCN) Coated Tool

2013 ◽  
Vol 372 ◽  
pp. 495-500
Author(s):  
Tasnim Firdaus Ariff ◽  
Mohd Syahidan Kamarudin ◽  
Mohd Amiruddin Haron
Keyword(s):  
Tool Wear ◽  
Temperature Rise ◽  
Cutting Parameters ◽  
Titanium Carbonitride ◽  
Depth Of Cut ◽  
Cutting Condition ◽  
Dry Machining ◽  
Wear Rates ◽  
Optimum Cutting ◽  
The Cost

Dry machining is environmentally friendly, clean and safe to be performed. Regardless of decreasing tool life due to lack of lubricants, choosing dry machining over wet machining may be a wiser choice since the cost of purchasing and disposing the cutting fluids can contribute to a higher cost. Wear rates, tool wear intensities and material removal rates (MRR) of TiCN coated tools using both dry and traditional wet machining on brass were studied with the aim in finding the optimum cutting condition from four different cutting speeds (207, 279, 372 and 498 m/min) with two sets of cutting parameters; depth of cut and feed rate (d = 0.1 mm, f = 0.2 mm/rev and d = 0.2 mm, f = 0.4 mm/rev). Temperatures at the tool-chip interface were measured to analyze the effects of temperature rise during dry machining. Cost analysis on machining cost per piece between dry and wet machining was performed. The optimum cutting condition for wet and dry machining of brass using TiCN coated cutting tool was found to be 498 m/min at d = 0.2 mm, f = 0.4 mm/rev. The tool tip temperature obtained from dry machining did not influence tool wear since the temperature rise is quite similar to the wet machining temperatures. The machining for the dry machining reduced to about 25-76% per piece when compared with wet machining.

scholarly journals Design Analysis of a Portable Manual Tyre Changer

2020 ◽  
Vol 5 (11) ◽  
pp. 1307-1318
Author(s):  
Ovundah King Wofuru-Nyenke
Keyword(s):  
Bending Moment ◽  
Steel Tube ◽  
Torsional Moment ◽  
Standard Size ◽  
Tube Size ◽  
Mechanical Advantage ◽  
Underdeveloped Countries ◽  
Wheel Rim ◽  
Cost Of Materials ◽  
The Cost

In this paper, an efficient, affordable, and portable manual automobile tyre changing tool was designed. The tool operates on the principle of second-class levers, where the load to be overcome is situated between the fulcrum and the effort point. The mechanical advantage (MA) of the bead breaker arm and pry bar assembly of the tool was determined to be 11.5. The standard tube size of the bead breaker arm that can withstand stress due to bending moment was determined to be a 2” (50mm) diameter Schedule 80 steel tube. Also, the dimensions of the standard hexagonal bolts to be used at the fulcrum and load point of the bead breaker arm are M12 × 1.5 × 75 mm, while the standard size of hexagonal nuts to be used with the bolts is M12 × 1.5 mm with a height of 10mm. Moreover, the mechanical advantage (MA) of the mount/demount arm and pry bar assembly of the tool was determined to be 5.22. Also, by comparing the angles of twist of two sizes of the mount/demount arm when the tool is used in mounting or demounting a tyre on a 16” × 7” wheel rim, the standard size of the mount/demount arm that can withstand stresses due to bending moment and torsional moment was determined to be a 60mm × 60mm × 5mm square tube. The cost of materials needed to fabricate the tyre changer summed up to ₦21,000. Ergo, the design provides an alternative portable and relatively affordable tyre changing tool that can be afforded by tyre technicians across Nigeria, and other developing or underdeveloped countries.

Improved Dynamic Thermal Model With Pre-Physical Modeling for Transformers in ONAN Cooling Mode

2019 ◽  
Vol 34 (4) ◽  
pp. 1442-1450 ◽  
Author(s):  
Lujia Wang ◽  
Lijun Zhou ◽  
Shuai Yuan ◽  
Jian Wang ◽  
Haolong Tang ◽  
...  
Keyword(s):  
Physical Modeling ◽  
Thermal Model ◽  
Cooling Mode

A New Approach to Calculating Fuel Temperature in TRIGA Mark I Research Reactors

2012 ◽  
Author(s):  
Jesse M. Johns ◽  
W. D. Reece
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Natural Convection ◽  
Transfer Coefficient ◽  
Forced Convection ◽  
Temperature Rise ◽  
Empirical Relationship ◽  
Convective Heat Transfer Coefficient ◽  
Fuel Temperature ◽  
Convection Correlation

Often a forced convection heat transfer coefficient is used to calculate the peak fuel temperature for a rectangular lattice TRIGA core even though the core is cooled by natural convection. The arguments for applying a forced convection empirical relationship are examined and another relationship is suggested. The peak fuel temperature was calculated using two different correlations, Dittus-Boelter and natural convection, for pool temperatures of 30°C and 60°C. The Dittus-Boelter correlation predicted a fuel temperature rise of 1.85°C for this difference in pool temperature, contrary to the predicted rise of 25.64°C from natural convection relationships. Experimental data shows that the relationship of fuel temperature rise with increasing pool temperature is more accurately represented by the natural convection correlation than with Dittus-Boelter. Using a derived natural convection correlation, the calculated peak fuel temperatures then closely match measured data. A procedure was developed to access convective heat transfer coefficient changes in the cladding gap as a function of reactor power for the hot channel which are similar to those presented in literature.

Thermal Model of Disk Coil With Directed Oil Flow

2008 ◽  
Author(s):  
Shahram Khalil Aria ◽  
Sahar Samsami
Keyword(s):  
Mathematical Model ◽  
Optimal Design ◽  
Temperature Rise ◽  
Thermal Model ◽  
Hot Spot ◽  
Exact Location ◽  
Oil Flow ◽  
Transformer Winding ◽  
Spot Temperature

In this paper, a developed mathematical model for temperature rise calculation is briefly described. In this model, at first, load loss of a transformer winding with forced directed oil is calculated and the winding temperature rise along the horizontal ducts and vertical ducts is computed. Then hot spot temperature and its exact location is determined. The model can also be used for optimal design of winding in size and cooling. Finally the results are given and compared with experiment values.

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