NuMAD is a user-friendly, X-windows based (GUI) pre-processor and post-processor for the ANSYS ® commercial finite element engine. It is designed to enable users to quickly and easily create a three-dimensional model of a turbine blade and perform structural and modal analyses. While users need no previous knowledge of the ANSYS® analysis package, experience with finite element methods is required to use NuMAD effectively. Model types accessible through NuMAD include three-dimensional beams, three-dimensional structural shells, and three-dimensional structural solids.
Given the complex geometry of most wind turbine blades, structural modeling using the finite element method is generally performed using a unique model for each particular blade analysis. Development time (often considerable) spent creating a model for one blade may not aid in the development of a model for a different blade. NuMAD has been developed in an effort to reduce model development time and increase the usability of advanced finite element analysis capabilities. Users may import blade geometry descriptions from other packages or interactively "build" blade geometries by selecting airfoil profiles, chord lengths, etc. Both structural (deflections, stresses, and strains) and modal analyses (natural frequencies) may be performed. The modal capabilities allow for both unstressed and prestressed (spinning) blades. The structural analysis allows for both static and dynamic loads as well as linear and non-linear buckling solutions. NuMAD contains databases of commonly used airfoils, materials, and load cases to speed model creation. The materials database contains both isotropic and composite materials and all databases for materials, loading conditions, and airfoil profiles are text-based and may be easily modified or augmented. For instance, a new material may be added to the materials database by simply editing the appropriate file with an editor or word processor and entering the properties of the new material. The new material is visible to NuMAD for all subsequent analyses.
NuMAD contains a tutorial of manufacturing guidelines to aid users in creating "manufacturing friendly" geometries. In addition, error checking is employed throughout the package to warn or prevent users from specifying unmanufacturable blades. Due to the utilization of a commercial finite element package, ANSYS®, state-of-the-art finite element analysis capabilities may be incorporated into NuMAD rather than developed from scratch. Future capabilities and improvements in ANSYS® may be quickly incorporated into NuMAD. For more information, or for the most recent version of NuMAD, contact:
Daniel Laird
Sandia National Laboratories
Albuquerque, NM 87185-0708
(505) 844-6188
NOTE: NuMAD is currently available to U.S. entities only.
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