.. _what_wisdem_can_do: WISDEM capabilities =================== Previous sections in the documentation have focused on :ref:`how_wisdem_works` at a high-level without delving into WISDEM's modeling assumptions and coding implementation. This page covers some of those details, explains when to use WISDEM versus other software packages, and where WISDEM's capabilities start and stop. What WISDEM can do ------------------ WISDEM as a conceptual-level design tool ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Because WISDEM models the entire turbine, from wind to LCOE, it is helpful in capturing system-level effects of changes in designs. This makes WISDEM useful at the conceptual design level to help down-select from many potential designs to the most viable designs. Computational expense ~~~~~~~~~~~~~~~~~~~~~ Depending on the model complexity, the disciplines included, and the discretization levels, design problems take on the order of seconds to minutes to solve using WISDEM. For example, tower optimization with fixed loads may take approximately 10 seconds, whereas full system optimization controlling the blade twist takes 5-20 minutes. Past design problems solved using WISDEM ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Since its creation, WISDEM has been used in a variety of problems for many different turbine designs. An overview of these problems is provided below with links to the studies where the results were presented. This is not an exhaustive list and WISDEM's capabilities have changed over the years, but this table is meant as a quick glance at some of the problems that WISDEM can tackle. .. list-table:: Previous problems solved using WISDEM :widths: 10 10 10 10 :header-rows: 1 * - Disciplines considered - Problem size - Design variables - Publication link * - Aerostructural blades, tower, costs - 15 design variables - | Chord, twist, spar cap thickness, | TSR, rotor diameter, machine rating - `10.2514/6.2013-201 `_ * - Aerostructural blades, tower, nacelle - 35 design variables - | Chord, twist, spar cap thickness, | precurve, TSR, tower height, | tower diameter, wall thickness - `10.1002/we.1972 `_ * - Tower - 6 design variables - Tower diameters and wall thicknesses - `Report `_ * - Generator/drivetrain - 7 design variables - Generator design parameters - `10.2514/6.2018-1000 `_ * - Aerostructural blades, rail transport - ~20 design variables - Blade twist, chord, spar cap thickness - `Paper `_ What WISDEM cannot do --------------------- WISDEM cannot model time-varying effects ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Because WISDEM is developed to tackle preliminary and conceptual design problems, physical phenomena cannot always be captured accurately. Specifically, WISDEM uses steady-state models, which means that time-varying aspects of turbine design cannot be examined using WISDEM. This means that any phenomena related to cyclic, transient, stochastic, or resonance-induced loads should not be studied using WISDEM. That being said, portions of WISDEM can be connected to other software, such as OpenFAST, to take advantage of WISDEM's computationally efficient systems-approach while also including higher-fidelity models. WISDEM is not a push-button solution to turbine design ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ It would be nice to have a tool where you press a button and receive an optimal turbine design. However, design optimization requires expert knowledge to perform correctly and interpret the results. WISDEM exists to minimize time needed to evaluate possible turbine designs by providing a framework and set of models. This enables turbine designers to more quickly assess performance trade-offs and make decisions based on the results from WISDEM. When to use tools other than WISDEM ----------------------------------- WISDEM is useful for a subset of wind turbine design problems. If you need time-varying effects, controllers in the loop, or more complex floating offshore capabilities, WISDEM is not the correct tool. WEIS and OpenFAST are two other software packages that meet different needs. When to use WEIS ~~~~~~~~~~~~~~~~ As part of the `ARPA-E Atlantis program `_, NREL is developing `WEIS, the Wind Energy with Integrated Servo-control toolset `_. WEIS enables studies of floating offshore wind turbines using multifidelity design processes. This tool is especially useful for doing optimization of the full floating turbine system and includes integrations for WISDEM, OpenFAST, and other existing NREL codes. When to use OpenFAST ~~~~~~~~~~~~~~~~~~~~ `OpenFAST `_ is a well-established higher-fidelity tool for turbine simulation. Whereas WISDEM and WEIS are design for design optimization, OpenFAST focuses on turbine analysis. OpenFAST gives more physically accurate results but has a much larger computational cost than WISDEM. OpenFAST has been used across multiple decades by hundreds of researchers for a huge number of research projects.