Windmill Tower Research Articles

Comparison of Seismic Response of Mono and Hybrid Structural System for Tall Windmill Tower considering Near-field and Far-field Earthquake

The windmill towers are the tall structures which are used as supporting mechanism for mounting the nacelle and rotor of windmill. These tower structures are conventionally steel structures with monopole configuration. It may be possible that these towers are installed in area of high earthquake risk and they are subjected to natural disaster like earthquake during its life span. The conventional monopole towers are not useful for very tall windmill tower in seismically active regions owing to slender effect. To reduce damages in conventional monopole tower constructed in near filed seismic regions, the new hybrid structural system which is blending of monopole and lattice configuration is proposed in present research. The mass and stiffness of structure are important parameters to resist the seismic forces, therefore in present research, new structural configuration is proposed which gives more stiffness to structure. The 125 mt high conventional monopole windmill tower is modelled in the numerical simulation and appropriate model of hybrid tower is also modelled in FE software. Both monopole and hybrid towers are subjected to natural disaster like earthquake, considering different near field and far filed Seismic excitation. Detailed dynamic analysis of both towers was carried out and response of monopole and hybrid tower was compared for parameters like displacement in time domain, baes shear in time domain and response spectra of structure. From the results obtained using numerical investigation, it is concluded that the innovative hybrid structural system is more effective in tall windmill tower and can be used efficiently to resist the natural disasters like earthquake.

Experimental investigation and optimization of submerged arc welding on Windmill tower using Genetic Algorithm

Submerged arc welding (SAW) is a high quality, high deposition rate welding process commonly used to join plates of higher thickness. In this research endeavour, Submerged arc welding process which has high industrial utility particularly in the area of welding of thick plates and pipes is optimised and the degree of influence of critical welding parameters on the quality of weld for Windmill towers is studied and estimated. Submerged arc welding has enough scope of potential research as it involves complex interaction of different welding parameters. The targets of this research attempt are to perform experimental investigations to analyse the impact of selected critical submerged welding parameters viz. Current Voltage, Standoff distance and Travel speed on the quality of welded bead, their level of influence and finally the optimum values to create best quality weld in thick pipes to make Windmill towers. the output of the research will benefit the Windmill tower manufacturing industries and the practising engineers of the same Field.The final experimental setup is the design of experiments (DOE) where an orthogonal array is constructed for four input process parameters a) Welding current, b) Voltage c) Standoff distance, d) Travel speed to the value of temperature. A Mild Steel (material specification S355/S355 NL+ Z25) is selected for analysis in 09 experiments where ultrasonic testing is performed to find the defect in welded joints. A probability distribution curve is drawn with the help of MINITAB software to ascertain the validity of the experiments where the results fall close to the mean value. Using the ANOVA, regression and RSM model a linear equation is obtained and feeding this equation in Genetic Algorithm to get final equation. To get desired to be minimum uses of resources, investigation into effect of process parameter on performance parameter and its optimization is necessary.

Design and analysis of wind pump for wind conditions in Pakistan

The unique thing about this research work is that it is the first comprehensive study out of all its kinds in Pakistan. Pakistan is an agricultural country and faces dearth of water resources availability for crops. This research work is very inevitable because it fulfils the water needs and also helps to minimize the energy deficit. This research article represents the means of wind speed data collection, design of wind-driven water pumping system and analysis of the design under different wind conditions in Pakistan. Wind speed data for province Punjab and Sindh are collected from Global Wind Atlas, Pakistan Meteorological Department and World Weather Online. First, design calculations have been made on the basis of analytical methods. Then proposed design is analysed using ANSYS Fluent Simulation models. Wind energy input, lift and drag on blades, rotor power output transmitted to the pump and water discharge from the pump have been calculated and verified from the simulation results. It has been shown that for any rotor size windmill produces maximum power output when angle between blade chord and axis of blade rotation is in the range of 23°–27°. Recommended height of windmill tower for 8–12 ft rotor diameter is 35–50 ft. Designed wind pump system can lift the ground water from 50 ft depth and discharge depends upon the size of windmill used. From the outcomes of the analysis, different designs having different power output and water pumping capacity have been proposed for different operating and wind conditions in the country.

Scale down Approach to Solve Distortion Problem in Case of Wind Turbine Tower Fabrication

Submerged arc welding (SAW) process is extensively used in major industrial application such as wind turbine towers and ship building industries for joining of larger thickness (~10 to 50mm) of similar and dissimilar materials. However, other joining processes are not popular to weld larger thickness compared to SAW. In welding, one of the major problems is distortion, which destroys the dimensional stability of the component, a major concern in manufacturing. Simulation of larger thickness component will increase the simulation time. Therefore, an attempt has been made to evaluate a 3 - dimensional finite element analysis (FEA) using SYSWELD to study the effect of the joining of two similar shells of High Strength Low Alloy (HSLA) steel through scale down model in the ratio of 10:1. To reduce the simulation time, the two shells of steel having 400mm diameter and 2mm thickness are modelled and simulated with single pass GMAW process using eight different welding sequences as per welding procedure specification (WPS) using SYSWELD. Results show the simulated welding sequence no. 4 has a considerable amount of reduction in distortion of 1.526 mm compared to that of other sequences. Welding sequence no. 4 is then followed by actual windmill tower fabrication, which resulted in reduced distortion level of 5 mm.

Impact Factor Identification for Switching Overvoltage in an Offshore Wind Farm by Analyzing Multiple Ignition Transients

This paper investigates the impact factors of switching transient overvoltage (SOV) in an offshore wind farm (OWF) by analyzing multiple ignitions of a vacuum circuit breaker. The statistical features of transient overvoltages, which occur under real switching operation scenarios, are analyzed based on the measurements in a laboratory platform that is built according to the configuration of an actual OWF. Next, an OWF simulation transient model is established considering high-frequency characteristics of circuit breakers, which is verified to be able to calculate the SOV accurately. Based on the developed OWF simulation model, the occurrence mechanism of SOV is discussed in detail by studying characteristics of transient voltage and current during multiple ignitions within a vacuum circuit breaker when it is switched OFF. Then, the key impact factors of switching- OFF induced overvoltage are identified, which include the inter-phase capacitance of cable in a windmill tower, the actual operating capacity of a wind turbine generator, and the single-phase inlet capacitance in terminals of a wind turbine transformer. Finally, the recommended configurations are given for the transient mitigation in an OWF.

Wind Farm: Four Variations

Wind Farm:Four Variations Jeff Gundy (bio) It is time for all the heroes to go homeif they have any … -William Stafford, "Allegiances" A big wind farm runs across the farm I grew up on and for miles to the west and north, a hundred or so towers combing the wind day and night, their giant arms turning, red lights blinking in unison through the nights. Some communities have fought to keep them out, claiming they kill birds, confuse human thought patterns with their churning, even disturb weather patterns, or might, or could, but here they are. They seem strange and wonderful to me, but I'm only around for a couple of days once or twice a year when we make it out to see my parents. The beauty of windmills is awkward and pragmatic, like the great blue heron's—or, better, the great egret, which is snowy white as the windmills. A beauty years in the making, expensive and complicated, an engineered and calculated beauty requiring access roads and giant [End Page 5] cranes, buried cables linking the great spindly machines. They are lonesome even in their clusters, keeping their distance, the way farmers have always been lonesome. The giant blades thrum their two notes day and night, yielding to and using the invisible wind, sifting it for power, sending it off to be used with no knowledge of where, of how. I've never seen an egret or a heron near the farm. A few might wander through the area, dip down to hunt in Scattering Point Creek to the east, but there's very little open water on the wind farm. I've been gone for nearly half a century, yes, but still I'm pretty sure they're rare. On the farm where I grew up, as far back as I can remember, a big raw steel windmill tower stood in place for decades, unused, a little rusty but sound. A buried electric pump pulled water from our well. The windmill on Vernon's place was still working, I think, when I was young—I remember a water tank between the legs. Electric pumps was more reliable, more practical, much less picturesque. When did those towers come down, and who did the work? If I had been a bolder kid I would have climbed them. I don't think I ever did, at least not high. I think now that my dad took the ladder down to keep us kids on the ground. That would have been sensible and tragic, and entirely fitting. Our well was reliable but the water was not good—sometimes full of rust, sometimes rotten-egg heavy with sulfur. My dad spent lots of money on treatment systems, hours trying to adjust and cajole them into working. The new windmills are something else entirely. Some people call them ugly, mostly for reasons having nothing to do with aesthetics. I suspect the resistance to wind farms is more political than people want to admit, but I also must admit I don't really know. If it's ugly we're talking about, though, we need to talk about the whole enterprise of industrial agriculture, the gridded landscape and the skinned prairies turned to monocultures, herbicides, pesticides, chemical fertilizer, all the rest. The roads, like a set of giant bars across a third of a continent, practical in the extreme if you're not a pheasant or big bluestem or a nomadic hunter-gatherer. [End Page 6] I Hear the Drumming There's a new song, Rick said, a protest song, it's pretty good. He was a Latino kid from Chicago who'd come to live at the Children's Home. Some of them were pretty tough, but Rick and his brother Tony just wanted to play music. They could do covers with every note perfect. I was equally in love with the music, could find the chords and keep a tune, but already I could tell that precise imitation would never be my strong suit. This was summer 1970 and I'd just escaped from high school. We'd ridden a bus all night to someplace in the Smokies...

Dynamic Analysis of Innovative Hybrid Wind Mill Tower with Soil Structure Interaction

Dynamic Analysis of Innovative Hybrid Wind Mill Tower with Soil Structure Interaction

Old Windmills in Scotland, with Special Reference to the Windmill Tower at Dunbarney, Perthshire

The surviving remains of the Dunbarney Tower are described in detail and a reconstruction is presented. There is no date on the tower, nor on the mansion house, but the doo'cot at the side of the approach to the house bears the date 1697 and the initials J.C. (John Craigie). The masonry of all three buildings is the same in appearance. The windmill is thought to have been built in the second half of the seventeenth century perhaps continuing in use for a hundred years.

Activity of Blowflies and Associated Insects at Various Heights above the Ground

When one is working with insect traps, baits and repellents, it is important to know the responses at different heights above the ground of the insect being studied. Questions arise as to whether an insect trap for certain pests should be placed near the top or in the center of a tree, whether a flytrap could be set more advantageously on top of a windmill tower than on the ground, or at what level status tests for insects should be made. In April, I930, while a study was being made of the status of blowfly parasites in different localities, interference with the baits by dogs necessitated the placing of the bait containers in trees. It was suggested that the increased height might affect the extent of parasitism. To determine this a test was made at Uvalde, Texas, in which jars containing meat were exposed at various levels, permitting blowflies and their associated insects to breed in the meat. This test was begun in June, 1930, and continued until September; it was repeated during the same months in I93I. The author is indebted to the following specialists for determination of specimens: Diptera, J. M. Aldrich, E. W. Laake, David G. Hall; Hymenoptera, A. B. Gahan; and Coleoptera, E. A. Chapin, H. S. Barber, W. S. Fisher.

Experiments on Wind-Pressure

FURTHER experiments on wind-pressure were described by Dr. T. E. Stanton before the Institution of Civil Engineers on December 3. The first part of this research, of which the results were communicated to the same institu tion in December, 1903, was the investigation of the result ant pressure and distribution of pressure on flat plates normal to and inclined to the direction of a uniform current of air. The value of the constant K in the pressure velocity relation P = KV2 was found to be 0-0027, a result some what smaller than those found by Dines, Frowde, and Langley. On the completion of this part of the work it was decided to make observations on flat surfaces of areas ranging up to 100 square feet when exposed to the wind, since general experience tended to show that in actual Winds the velocity of which was not uniform over time or space, the mean pressure per square foot on a large surface was considerably less than that on a small one. For the purpose of the work a steel windmill tower was erected n the grounds of the National Physical Laboratory at Teddington. The experimental boards and models of structures were attached to a light framework carried by:he cap of the tower, the height of the centre of the boards rom the ground being 50 feet.