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Design Considerations of Solar Water Heating System: A Review
Get PDFSolar energy is considered as one of the best alternative sources of energy since it is clean and sustainable for the environment. Extensive research on various aspects of solar water heating systems has been done in order to increase the overall efficiency of the system and optimize the design. The size of the system depends on temperature required to the customer, solar radiation, arrangement of the solar system, geographical condition and so on. Hence, it is important to design the SWH system, considering such parameters to assure maximum benefit to the user. This paper exclusively discusses the design aspect of the components of the SWH system. The first part of the paper deals with the summary of different system components that includes collector, storage tank, heat exchanger and coating on pipes. The second part of the paper discusses the advancement in the system in terms of various parameters such as overall efficiency, temperature, flow rate etc. The paper also includes the discussion on the use of simulation tools, numerical modelling and researches in heat transfer components that show prominent technological advancements in SWH systems. In addition to that, the paper comprises ample discussions regarding the use of SWH systems in a developing country like Nepal. Different tracking and data acquisition systems used in the countries having similar climatic, topographic and geopolitical conditioning were studied to draw optimum information on design of the solar system for Nepal. The review shows that a major portion of the SWH system design includes the collector sizing and its design because the overall system efficiency depends majorly on the collector efficiency. The various approaches for improvement in performance and efficiency, and adaptation with the recent advances has helped to enhance and upgrade the design of solar water heating systems
Homotopy perturbation transform algorithm for solving (2+1) dimensional type of the Zakharov–Kuznetsov equations
Get PDFIn this research, homotopy perturbation transform method (HPTM) is used to present the approximate analytical solutions of (2+1) dimensional type of the Zakharov–Kuznetsov nonlinear partial differential equations. This method gives solutions without any linearization and discretization or restrictive assumptions. Special cases of and are chosen as examples to show the capability and efficiency of the method. Maple 19.0 software is employed to compute the series generated from the algorithm. The results show that HPTM is very simple, reliable and effective in solving nonlinear problems
Modeling of Energy Requirement for Tillage Operations in a Sandy Loam Soil
Get PDFTillage, the mechanical manipulation of soil, demands a huge amount of energy in order to accomplish various tasks during field operation. Field tests and evaluation were conducted on 40 different tractor makes and models with matching implements on a sandy loam soil between 2005 and 2011 by the officials of the National Centre for Agricultural Mechanization (NCAM), Ilorin, Nigeria. Implements used for the trials were tractor mounted disc plough and off-set disc harrow. Each tractor was operated on an area of 0.25 hectare (25 m × 100 m) in a randomized complete block design (RCBD). Parameters measured include travel speed, actual and total time of operation, field efficiency, field capacities (effective and theoretical), depth and width of cut, average soil moisture content, average soil bulk density and average soil cone index in order to determine the energy requirement for each tractor-implement combination. Two models for predicting energy requirement during ploughing and harrowing operations were developed using 36 tractor test data. The multiple linear regression method was used for developing the two models. The remaining 4 tractor test data were used for cross-validation. The resulting model equations for ploughing and harrowing operations gave R-squared values of 0.859 and 0.776, respectively. Results obtained from the predicted energy requirement values when compared to that of the observed energy requirement values for both ploughing and harrowing operations gave correlation coefficient values of 0.927 and 0.881, respectively. Cross-validation results for the models developed for energy requirement during ploughing and harrowing operations gave test error values of 4672.3 J m-3 and 2721.1 J m-3, respectively
Study and Design of Pendulum Assisted Hand Water Pump
Get PDFThe designed pump consists of a normal hand pump and a pendulum, held together into a mechanism by a metal structure. This pendulum pump aims to provide a solution for lifting water manually, which requires a large human effort when operated continuously. It is based on a very simple principle of the pendulum, lever two-staged oscillator mechanism. With the help of this principle, the reciprocating motion of the piston in the pump is obtained using the oscillation of a pendulum. The pendulum pump was designed using different calculations and was fabricated adding frame, springs, pendulum to normal piston pump for the actual experimentation. The project purely deals with the mechanical aspect of the pendulum pump, where an experimental approach is implemented to conclude. The average discharge of water at 30°, 40°, 50° and 60° swing angles were 51ml, 59ml, 70ml, 98ml respectively which concluded that the discharge of this designed pump extremely depends on the swing angle of the pendulum as water discharge is increased with increasing angle as seen from experimentation. Also, from experimentation, this designed pump pumps out approximately 9% of more water than a conventional hand water pump taken average discharge of normal pump as reference under the same circumstances. As this pump can be operated with minimum effort compared to a normal hand pump, it can be operated by people of any age and even by physically challenged people. This machine can be useful for small scale irrigation, handling of wastewater, lifting water to small height for household purposes or to lift water from well
Structural Optimization of Simple Span Bridge by Adding Truss Structure
Get PDFA truss is a structure that involves members assembled into connecting triangles so that the overall connection behaves as a single object. Its application is in industrial and building construction. This paper presents a study about optimizing a simple span bridge in terms of stress, the factor of safety, and maximum displacement by adding different structures. A simple span bridge having a span length of 12m was modeled using SolidWorks’s finite element analysis approach. A uniform initial load of 5000N was applied to the beams in all cases to determine safety factors, which helps determine the maximum allowable force, the maximum displacement, and the ultimate yield stress. The result shows that a simple span bridge has an efficiency score, the maximum displacement of 24.17, and 749.9 mm, respectively. Upon design modification by adding Howe truss structure, floor beams, and lateral bracing, a considerable increase in efficiency score was observed with reduced displacement. Among all cases, the optimized bridge has an efficiency score and maximum displacement of 83.69 and 63.08 mm, respectively. This paper aims to find the optimized structure to its full capacity for the given material
Aerodynamic Performance Analysis and Evaluation of NACA 653-218 Airfoiled Aircraft at Different Blended Winglet Configurations
Get PDFThe research project explores specifically airfoiled (NACA 653-218) wing model for its aerodynamic performance, basically, the ratio of coefficient of lift to that of drag, on adapting a non-twisted classical winglet, also known by the name of Whitcomb (blended) winglet, by configuring its geometrical parameters. After reviewing the state-of-art of this technology used in modern aircrafts both in commercial/passenger and military, the only parameter that has significant influence on the particular results we were looking for, which is the increased CL/CD ratio relative to clean wing, was the cant angle of the winglet. When simulated using ANSYS Fluent solver, 3D-flow at the wingtip was visualized for both winglet and without winglet cases which showed the reduced intensity of the vortex at the tip, in the former case than the latter. Gain of 8-12% was found in CL/CD ratio in 30° canted winglet case after solving and plotting the percentage gain in CL/CD ratio relative to that of clean wing without the winglet against general angle of attack, for different cases where winglet cant angle was the only variation in geometrical parameters. Validation of the results was done by performing the grid independence and the convergence tests. The results were analyzed on the basis of relation of local angle of attack along the winglet span (αwinglet) with the general angle of attack (α). Near vertical winglets (lower cant angle) cases were found successful in maintaining zero pressure gradient at the tip, lowering the intensity of vortex and downwash intensity but a failure in harnessing the lift force like near horizontal winglets (highly canted winglet) and vice versa
Investment analysis of integrated milling-sieving-dewatering machine for grain slurry starch production
Get PDFEconomic viability of a continuous process milling-sieving-dewatering machine for grain slurry starch production was evaluated in this study using benefit-cost methodologies in order to encourage its wide acceptance/adoption. Benefit cost ratio, payback period, net present value and accounting rate of return constitute the economic parameters of the machine evaluated subject to prevailing economic indicators/market prices of materials in Abia State of Nigeria in 2020. Results revealed that the machine's benefit-cost ratio, payback period, net present value and annual rate of return as 1.86 years, 1.75, 1.75 for every $1 spent The payback of 1.86years is far less than 10 years useful life of the machine while its 31.41% accounting rate of return outweighed banks maximum fixed deposits return of 16% and prime lending rate of 29% in Nigeria. Thus, the machine is recommended for advancement of grain slurry food processing sector due to its positive capital recovery prospect
Design and Fabrication of Animal Waste Cleaning Machine
Get PDFCleaning is an essential and unavoidable part of life, and cleaning animal shed waste is a time-consuming activity that may be better spent on something more productive. During discussions with dairy farmers in Nepal, it became evident that animal waste collecting equipment was required. One of the primary reasons for this requirement is labor scarcity, which is caused by employees’ dislike of picking and collecting animal dung manually. Animal waste cleaning machine provides a strategy for collecting animal dung and cleaning the space without putting people in close contact with the dung. A chain drive mechanism is used in this machine. The dung is collected with the help of picker/rubber pads that are welded to the chain, then dropped into the collector, and the process is repeated. The chain is coupled to a 12V battery-powered dc motor. The machine is cost-effective and saves time by reducing human labor. It may also be utilized as a stand-alone device in remote areas
Numerical Investigation of Pelton Turbine with Experimental Validation
Get PDFComputational Fluid Dynamics (CFD) has been established as a prominent tool for the effective analysis and optimization of hydro-turbines. Various CFD codes, both commercial type and open-source type, are being used in the industry for flow simulation and optimization. For impulse turbines like Pelton, the numerical simulation requires solving of various complex phenomena like multi-phase fluid interaction, multi-reference frame study, jet-bucket interaction and free-surface transient flows. A number of simplifications has to be made in terms of the geometry and flow physics for solving the flow problem in reasonable time and less computational cost
Enhancing indoor thermal comfort and energy efficiency in residential buildings of hot humid region of Nepal – A case of Biratnagar Metropolitan City
Get PDFEssence of indoor thermal comfort and reduction of active power consumption to meet indoor thermal needs has been a keen interest of academia around the globe which has resulted into formulation of strict guidelines for indoor environment requirements in developed countries. Nepal on the other hand lacks the basic provisions when it comes to assuring indoor comfort. Studies shows that unscientific building construction has caused people to depend on changing food and clothing habits to accommodate to the present scenario of indoor environment. The main aim of this study is to address this underlying issue through passive interventions such that both indoor thermal comfort and energy efficiency can be achieved. The study is based on evaluating the effects of various passive and energy efficient building technologies on indoor thermal environment through building energy modeling using EnergyPlus computational engine. Present scenario of indoor thermal environment of residential buildings at Biratnagar and retrofitting measures including insulation, glazing variants, shading, air tightness and others that can enhance indoor thermal comfort whilst enhancing energy efficiency is presented in this paper. In present context, the indoor thermal comfort as indicated by ASHRAE (American Society of Heating Refrigeration and Air Conditioning Engineers) 55 Adaptive Model 80% Acceptability limits is only 32% of total hours in a year, i.e. indoor comfort is compromised for above 5800 hours (equivalent to 8 months) with `hot' to `sweltering' indoor environment. Effects of 8 passive design interventions on residential building was analyzed based on the thermal load reduction potential and increase in acceptable limits of indoor comfort hours. It was found that combination of various design changes would help achieve up to 86% indoor thermal comfort hours and reduce annual thermal load by 68% relative to the base case scenario The study shows that incorporating passive techniques on Nepalese residential buildings can assure indoor comfort and reduce active heating/cooling demand