An interactive tool to predict VAWT performance using streamtube models
Mathematical models have been developed to predict the performance of vertical axis wind turbines (VAWTs) since the early 1970s. Each of these models was studied by many researchers through the late 1980s, and have been successful in predicting VAWT performance including correlation with data. However, these computational tools were not easily available and some were relatively demanding in terms of computational capacity. Further research in this area became less rigorous in the 1990s as little success were obtained from VAWT commercialization. With the current increased interest in developing renewable energy, there is renewed interest in VAWT for small wind applications. A variety of VAWT designs are beginning to appear in the market and their performance needs further investigation. Hence, the goal of this project is to develop an interactive computational tool to predict the aerodynamic performance of VAWTs that is computationally less demanding. ^ Three primary models have been studied: streamtube models, vortex models, and local circulation models. Streamtube models are more appealing compared to the others due to their simplicity and relatively good estimate of the actual performance as compared to experimental data. The interactive computer tool developed herein is based on the double multiple streamtube (DMS) and multiple streamtube (MS) models. The latter was included for comparison of the results obtained. Both MS and DMS models involve iteration for the induced velocity and the computation of the corresponding performance parameters. ^ Based on these streamtube models, a computer tool VAWTGUI was developed using MATLAB. It is an interactive graphical user interface (GUI), which enables VAWT geometries and incoming velocity profiles to be defined by the user. VAWTGUI provides various plots to enable the performance of the turbine to be evaluated. The results obtained from several VAWT configurations are demonstrated to illustrate VAWTGUI's usefulness for future studies.^
Sanford Fleeter, Purdue University.