Archive for September 2014
The Velkess Flywheel: A more flexible energy storage technology
(Phys.org) —A new Kickstarter project called Velkess (Very Large Kinetic Energy Storage System) has recently gotten underway to bring an inexpensive flywheel to market. The project is headed by Bill Gray, who has taken a unique approach to flywheel design—a flexible rotor made of "E-glass," a common fiberglass used in everything from sporting goods to shower doors. Rather than use advanced carbon-fiber composites manufactured to exact tolerances, Gray's soft rotor flexes in response to destabilizing forces. It is thereby able to adjust to speed transitions that confound other designs.
With the memory of other flywheel venture failures, like Beacon, fresh in mind, Gray has cast the issues a little differently. While carbon fiber reinforced polymer is 6 to 8 times stronger than E-glass, he notes that E-glass is 10 to 20 times stronger per dollar. Similarly, E-glass will store 10 to 20 times more energy per dollar. The current prototype floats on a magnetic bearing assembly that can handle 2kW of power, and store 0.5 kWh of energy. Their final device will need storage closer to 15kWh to meet the first projected 48-volt off-grid power backup.
This scale up means replacing the 25lb flywheel rotor used for the video footage with a 750lb rotor. Scale-up creates new issues including special production runs for magnets able to support that load, and also equipment to safely handle all that magnetic forcefloating around. Details of the bearing-motor assembly are still not publicly available. Since the rotor design is essentially cantilevered from the motor in the vertical plane, anything here is possible. For example it appears that the rotor has a low-end speed of 9000 RPM. That would be where it is not even transitioning power. To get to the 15kWh regime, we are probably talking about a max RPM on the order of that of a jet engine.
Jet engine speeds are well above even the fastest comparable electric motor speeds. For example, high-speed spindles for machine tools, that might put out anything approaching say 30kW, would probably max out below 10,000 RPM—and these motors can cost over $50,000. Probably some fancy gearing is involved here, and therefore ample opportunity for unique combinations of bearings to be employed throughout the system.
Where mechanical bearings are to be used, they can have thermal sensors to detect any rise in temperature that would indicate a failure may be about to occur. The possibility for catastrophe due to fracture in one of the silicon nitride bearings can be therefore be greatly reduced. In an off-grid shutdown, the device would dissipate its energy in the form of exhausted hot air. As the rotor slowed over the course of ten hours, this would be a similar flow as a 1500-watt hair dryer might put out.
Gray expects the final units to be comparable in price to lead acid batteries while having a much improved lifetime. Also, the construction materials will be environmentally friendly. The rotor will operate in a vacuum and it is expected that only about 2 percent of its stored power will be lost to friction each day. These numbers make the newflywheel design look like it could be a viable alternative not just to batteries but also to other green schemes like compressed air storage, or pumping water uphill. If the Velkess project can get backing on a scale similar to what these technologies have attracted, flywheels may have finally come of age.
Introduction to I.C Engine
In this article you will learn about the I.C Engine
How its works?
Engine Clessification
Animation of I.C Engine
Introduction to Mechanical Vibration
Here you will learn about what is a Mechanical Vibration?
and
Types of Vibration
S.H.M
Principle to superposition applied to S.H.M
Beats
Mechanical Vibration Theory & Application by S Graham Kelly
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Transformer Manufacturing Report
Elmetec Private Limited is the pioneer manufacturer of electrical goods in Pakistan. The company has always been contributing towards the advancement and development of the engineering sector in Pakistan by introducing a range of quality electrical equipments by producing hundreds of engineers, skilled workers and technicians through its apprenticeship schemes and training programmes.We recently have done our internship in Elmetec, in which we got training from its Distribution Transformer unit. The internship basically revolved around the transformer design, manufacturing, I&QC and maintenance. The system, the style of working & the commitment of the employees in Elmetec is really exemplary.
The difference between the success & failure is doing things right and doing things nearly right, & Elmetec has always tried for success & that is why it is known to be one of the leading companies in Pakistan.
In this report we have given a very brief review of what we have seen and learnt during our internship. we have mentioned all these as we have made an internship as according to the schedule. This report will give its reader knowledge about the Elmetec and power division especially about transformer unit.
we have made it possible to write each and every thing that we have learnt here. We have all our practical efforts in the form of this manuscript that’s the asset for our future career.
Automatic Bottle Filling System using PLC
Automatic Bottle Filling System using PLC
This is final year project for Control Engineering students on "automatic bottle filing system using PLC and conveyor belt". For this project Omron CPM2A PLC is used, which act as heart of the system and is programmed using Ladder programming. During this project sensor has been used to detect the bottle position that move along the conveyor belt at the low speed while the machine operates. The input signal that has been sent from the sensor to the PLC has being made as a reference. Signal in order to determine the output signal that exactly a same with the PLC programming language based on the user requirement.The prototype was mainly built by combining the mechanical design and the electrical designs. The system require three external DC power supply for input output devices, two AC power supply for supplying pump and PLC, and one 9V battery for buzzer. This report consist ladder programming, flow chart, block diagram used, prototype of the project, conveyor system, electrical design etc. to help you in making your project. Please treat this report as reference material for your final year project.
Project on Automatic Escalator System
Project on Automatic Escalator System
Automatic Escalator System is a very useful project and help in reducing the use of energy and providing efficient system. This project has variety of applications. The main part of this project are Human sensor, Micro-controller unit, driver unit and escalator motor. The whole system is automatic and when someone steps on the escalator, it senses it and according go up or down. This project is build using AT89S52 microcontroller unit and LM7805voltage regulator IC. The Micro-controller programs are written in assembly language. You can also Subscribe to FINAL YEAR PROJECT'S by Email for more such projects and seminar.
An escalator could be a staircase conveyor transport device for carrying folks between floors of a building. The device consists of a motor-driven chain of individual, coupled steps that move up or down on tracks, permitting the step treads to stay horizontal.Escalators area unit used round the world to maneuver foot traffic in places wherever elevators would be impractical. Principal areas of usage embody shops, searching malls, airports, transit systems, convention centers, hotels, and public buildings.
This project report contains circuit diagram, component description, requirement and aim of project etc. Use this project material for reference only.
Design of 120cc Single Cylinder Experimental Engine for Analysis of Intake Swirl and Multiple Ignition Sites
Design of 120cc Single Cylinder Experimental Engine for Analysis of Intake Swirl and Multiple Ignition Sites
The intent of this study is to design, build, and test a cylinder head with variable swirl and ignition sites. The design aspect used Solid Works Floworks to model airflow within the head and cylinder. Swirl rate and volumetric flow rate were calculated from the results. Many design iterations took place before a suitable design was accomplished.
Once the suitable design was reached, it was built using the rapid prototyping method known as 3-D printing (Fused Deposition Modeling). Valve guides and seats were installed in the head. Then valves, springs, and retainers were installed to allow for testing.
The inlet was created using stereo-lithography due to its smooth surface finish and thin walls. A pin wheel swirl measuring device was built to measure tangential rotation rate of gasses in the cylinder. The experimental head was tested on the University of Miami flow bench in the Internal Combustion Engines Laboratory.
The results of the experimental work and theoretical modeling were compared. The results matched closely. The difference between experimental and theoretical values for high swirl flow rates were less than 3% error and the swirl ratio was less than 10%.
For the low swirl scenario, error was less than 30%. The measured flow rate for the high swirl scenario was 28.87 CFM and the swirl ratio was measured as 2.87. SolidWorks Floworks created accurate results for the high swirl scenario and further experimentation should be conducted for different geometries.
Author: Seemann, Patrick
Source: University of Miami
An Optimization Based Approach to Visual Odometry Using Infrared Images
An Optimization Based Approach to Visual Odometry Using Infrared Images
The goal of this work has been to improve the accuracy of a pre-existing algorithm for vehicle pose estimation, which uses intrinsic measurements of vehicle motion and measurements derived from far infrared images.
Estimating the pose of a vehicle, based on images from an on-board camera and intrinsic measurements of vehicle motion, is a problem of simultanoeus localization and mapping (SLAM), and it can be solved using the extended Kalman filter (EKF).
The EKF is a causal filter, so if the pose estimation problem is to be solved off-line acausal methods are expected to increase estimation accuracy significantly. In this work the EKF has been compared with an acausal method for solving the SLAM problem called smoothing and mapping (SAM) which is an optimization based method that minimizes process and measurement noise.
Analyses of how improvements in the vehicle motion model, using a number of different model extensions, affects accuracy of pose estimates have also been performed.
Source: Linköping University
Author: Nilsson, Emil
Computer Aided Design of Side Actions for Injection Molding of Complex Parts
Computer Aided Design of Side Actions for Injection Molding of Complex Parts
Often complex molded parts include undercuts, patches on the part boundaries that are not accessible along the main mold opening directions. Undercuts are molded by incorporating side actions in the molds. Side actions are mold pieces that are removed from the part using translation directions different than the main mold opening direction.
However, side actions contribute to mold cost by resulting in an additional manufacturing and assembly cost as well as by increasing the molding cycle time. Therefore, generating shapes of side actions requires solving a complex geometric optimization problem.
Different objective functions may be needed depending upon different molding scenarios (e.g., prototyping versus large production runs). Manually designing side actions is a challenging task and requires considerable expertise. Automated design of side actions will significantly reduce mold design lead times. This thesis describes algorithms for generating shapes of side actions to minimize a customizable molding cost function.
The approach presented in this work leads to practically an optimal solution if every connected undercut region on the part requires three or fewer side actions. Results of computational experiments that have been conducted to assess the performance of the algorithms described in the thesis have also been presented. Computational results indicate that the algorithms have acceptable computational performance, are robust enough to handle complex part geometries, and are easy to implement. It is anticipated that the results shown here will provide the foundations for developing fully automated software for designing side actions in injection molding.
Author: Ashis Gopal Banerjee
Source: University of Maryland
Development and Optimization of Synthetic Jets for Active Flow Control
Development and Optimization of Synthetic Jets for Active Flow Control
The goal of the project is to simulate and analyze the near C-130 Hercules flow field and then evaluate the influence of passive and active flow control method. This carrier aircraft has been extensively used and is essential while cargos, troops or material supplies has to be delivered rapidly in difficult access areas to military troops or during disasters that require humanitarian supply.
The upsweep region in the aft fuselage leads to an increased drag, due to the highly detached flow and to strong upsweep vortices. The latter can be dangerous, by several means, during airdrop operations. For instance parachutes, while caught on the upsweep vortices can touch the empennage if they exit from the rear door. A good knowledge of the flow pattern around the aircraft is thus of particular interest to be able to control this flow by, for instance, attenuating the upsweep vortices. The ultimate goal of control device is to cancel any undesirable effect in the aft fuselage and enhance airdrop capability.
In this sense it was proved that the aft fuselage region is the site of highly complex flow. Indeed this region is characterized by a massive separation, highly three-dimensional, where one can observe a pair of counter-rotating vortices also called upsweep vortices. These vortices then interact with the lower side of the empennage and cause the flow to detach resulting in counterrotating vortices also called induced vortices.
Source: KTH
Author: Bennani, Patrick
Study of Data of a Wind Farm
Study of Data of a Wind Farm
Nowadays, due to global warming and the depletion of petroleum reserves, renewable energies have gained special prominence. At the moment, wind energy is the most successful renewable energy resource, and the technology to convert this wind energy into electricity has been very developed.
As a consequence, the costs per kWh of generation have decreased and it has become a competitive alternative for conventional fossil-fuel power plants to generate electricity.However, a lot of factors and variables are involved in wind power generation.
In the first part of this document, some of this factors like the Betz limit, the classification of wind turbines and its components, and the power curve of a wind turbine are explained.In the second part, the performance of a real wind farm is studied. The wind farm is called Es Milà, and it is located in an island called Minorca, in Spain.
Firstly, a description of this wind farm and the energy and electricity in Minorca is made.Then, with meteorological and power data of 2007 a thorough study of its performance is completed. In this study, first of all some meteorological aspects like wind direction, wind velocity and its distribution are discussed.
After that, the study focuses on electricity production, looking at the power curve, at the expected and the real production, and trying to explain a little of the reactive power.
Source: Linköping University
Author: Montoya Moyá, Joan
