Wind Load Calculations

iLevel® Forte™ Software Reaches 10000 User Milestone

Federal Way, Wash., July 27, 2011 – iLevel by Weyerhaeuser’s single-member sizing program for wood-framed structures – Forte™ software – is now used by more than 10,000 engineers, architects, home designers and other building professionals.  Introduced in fall 2009, Forte software is a powerful tool for sizing wood framing members, including joists, headers, beams, wall studs and columns.  Using this powerful software, a customer can size dimension lumber and engineered wood products, even accounting for seismic and wind loads.  Users prefer Forte software for the ease of use, ability to quickly compare alternatives, and report exporting capabilities that facilitate information sharing.  Forte software is available for free download at www.iLevel.com/Forte .

“In the building industry, we don’t have the luxury of time when working out solutions to design problems,” said Alan Hatcher, partner with Lane & Hatcher Engineers in Pensacola, Florida.  Hatcher recently became the 10,000thregistered Forte software user.  “With Forte software, I can acquire the answers I need quickly and accurately.  Plus, it’s intuitive and very easy to learn.  The first time I opened it, I was able to move through the member loading criteria quickly and could see a visual display of the results immediately.”

“Users tell us they can size members in a matter of minutes versus the hours often needed with cumbersome hand calculations,” added Ross Theilen, Director of Customer Software & Technology for iLevel.  “The speed and accuracy of Forte software lets them compare multiple solutions and pick the most cost-effective one – that’s not always practical when working by hand.”

“Another neat thing about Forte software is the JobTree, which allows you to organize your files and quickly switch back and forth between member types,” added Hatcher.  “Plus, in high-wind areas, you can input various wind load and exposure criteria and the software will analyze the member's lateral force stresses and requirements.”

Forte software is part of the iLevel®Modus™ suite of structural frame software, including Javelin®design software and Stellar®fabrication software.  Along with Estima™ estimating services, the iLevel family of software and services helps builders and building material dealers with consistently high-quality and cost-effective structural framing solutions.

Your Questions About Wind Turbine Designs |

The problem is very similar to the design of an airplane wing, except that the design has to shift from hub to tip to account for the increasing speed across the air stream as the distance from the hub increases. Think of the turbine blade as a wing that produces its lift in the direction that produces turning force. You want to maximize that force while minimizing drag forces in the direction of the air flow. So the optimum shape is an air foil similar to a wing, but turned so that the blade moves away from the concave side of the wing as it ‘lifts’ around the hub. Since the rotational velocity is low near the hub, the wing needs to be thick and wide, there. At the tip, the rotational velocity is high, so the wing needs to be thin and narrow out there. This is very similar to how propeller blades are shaped, except, there, you supply the rotation and the blade makes the wind.

In principle, a blade with a weight-cons might work as well as a greater number of blades, except that the weight-balances against only the weight of the blade, not the forces of drag that caused by the wind password. So, two blades are usually the lowest practical number. Then you have ot believe that every time a blade passes the tower, the air flow is disturbed, and if there are only two blades, a decline of great power, twice per turn. For this reason, three blades are probably the most common. But a higher number of blades can work, too, but this usually increases the cost more than it smooths the performance.

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Hey Wind, take a good look at Charles answer to your question, it’s worth reading several times. I have to agree that the Helix, or the “Darrieus Rotor” is really neat looking. It is far from an efficient design. This is exactly the thing that got wind and solar into so much trouble in the 70′s, the misinformation that circulated around and was accepted as gospel by everyone.The vertical axis wind turbines is one of the most inefficient in the world. That's why you do not see utilities by installing wind farms in their expensive, they would never pay for themselves. The typical VAWT has approximately 5 to 8% efficiency, far from the typical 3-bladed horizontal model, about 25 to 30%. But do not take my word for it is getting your hacks online information form as we that defeats the whole point of research first. Get the non-profit sites, such as AWEA.ORG or MREA.ORG, or better yet, take a trip to the library and check out some old books, such as wind power for home and business, by Paul Gipe, or something written by Mick Sagrillo. Mick Sagrillo has a fantastic discussion on any subject on the AWEA website by the way, it is considered by people in the company to be the guru of the modern wind energy.

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