Wind Energy Consulting Services
DARcorporation has been offering aeronautical engineering software and consulting services since 1991. Over the years DARcorporation has developed a unique expertise in aerodynamic design of wind turbines. Our experience includes designing, building and testing Horizontal Axis Wind Turbines (HAWT) and Vertical Axis Wind Turbines (VAWT) and have worked with many unconventional wind turbine designs. Our designs are optimized for best performance based on based on Computational Fluid Dynamics (CFD), Finite Element Analysis (FEA), structural analysis, wind tunnel testing and field testing.
Aerodynamic Design & Analysis
Blade Element Momentum (BEM) theory software is used for the initial aerodynamic design of the wind turbine blades. DARcorporation engineers developed and customized the software to handle any type of wind turbine configuration and blade shape. Airfoil design and analysis software is used to analyze and design the airfoils used on the blades. Computational Fluid Dynamics (CFD) software tools are used to simulate rotation and quantify the full power curve of the wind turbine. Pressure distribution over the blades is calculated and torque (and thus energy) curves are constructed. Once the aerodynamic design is finalized, a wind tunnel model can be designed, constructed and tested.
Structural Design & Analysis
Structural design is carried out after the aerodynamic design is finished. Aerodynamic loads in the form of pressure distributions from Computational Fluid Dynamics (CFD) or experimental data are mapped into a finite element model. Load cases are determined based on IEC design standards for load factors and typical wind cases. DARcorporation utilizes NEi NASTRAN to analyze the structure. Linear and non-linear cases are analyzed. The structure can be made out of steel, aluminum, glass fiber and/or carbon fiber or any combination thereof. A unique method has been developed by DARcorporation engineers to analyze the harmonic behavior of wind turbines. Unwanted vibrations are detected and designed out of the system.
Detailed modal analysis is carried out to determine the natural frequencies of the various components of the wind turbine. Frequency response and transient response analyses are also carried out to determine critical deflections under forced oscillations caused by changing wind direction. Interference between various components of the wind turbine is analyzed and the structure is designed as per the IEC or other regulations. The turbine is designed in such a way that the natural frequencies of the blades are different from the operating RPM. Detailed fastener analysis is carried out and all fasteners are sized appropriately. The entire structural design is conducted to simplify transportation and assembly. Detailed CAD for Finite Element Analysis (FEA) is generated in Siemens NX and can be translated into other CAD formats.
Testing & Calibration
DARcorporation will design or analyze the structure, whether it is made out of composites, metal or a combination of both. We will do analysis for strength, stiffness, flutter and overall system dynamics. We will select materials and provide layup schedules for composites.
Our team of highly skilled aeronautical engineers can test and analyze models in subsonic and transonic flow regimes. We can conduct flow visualization tests on models and provide qualitative assessments. We will also analyze stability & control and drag data derived from wind tunnel tests. We can test models ranging from 6 inches to 6 feet, using in-house test stands fully integrated with cutting-edge data acquisition systems to collect data in all six degrees of freedom.
DARcorporation will plan and manage all aspects of modeling, testing and data analysis. We will provide the perfect liaison with wind tunnel model manufacturing companies and perform model accuracy inspection. We will analyze your design or design the blades and aerodynamic surfaces for you, using Computational Fluid Dynamics (CFD) tools. We have developed our own in-house software for fast and detailed analysis of more conventional blades. Using these types of codes are generally faster than using CFD.
Wind Tunnel Testing
Depending on model size and wind speed requirements, wind tunnel models are tested at The University of Kansas (KU) or Wichita State University (WSU). Either a small generator or an electronic brake in combination with a torque sensor is used to measure the power output of the model. When using a generator a resistor box is attached to simulate the load on the generator and to control the RPM. With the different RPM's and the torque a power curve can be constructed. DARcorporation developed a unique wall correction method to correct the data from the wind tunnel for wall effects. Necessary modifications and changes to the design can then be identified.
Full scale prototypes are installed at test sites throughout the country. DARcorporation engineers will create a test plan and test the turbine for performance over a period of time. This test bed will provide data such as wind speed and wind direction, RPM, power performance characteristics, accelerations and loads. Data is then analyzed and detailed power curves are constructed.
Fabrication & Manufacturing
DARcorporation engineers can design, analyze and build the structure, whether it is made out of composites, metal or a combination. We will select materials and provide layup schedules for composites. We will do analysis on strength, stiffness, elastic stability, dynamic modes and responses, and flutter, etc.
Our 3,000 sq. ft. shop is equipped with tools and equipment specific to prototyping and manufacturing of aircraft and wind energy devices. Upon completion of the detailed design, a prototype wind turbine model can be constructed. Our prototypes range from proof-of-concept display models and wind tunnel models to full scale test turbines. Our facility is capable of manufacturing both metal and composite turbines. Loads and function tests can be performed for individual parts or full scale assemblies. In addition to designing your vehicle, we will keep us in close involvement in every step of its fabrication and assembly. We will ensure a high level of quality control, and all parts are checked for fit and finish. We can perform static load, dynamic normal modes, flutter and field tests to ensure that your prototype does what we say it will do.
The DARcorporation Advantage
Experience in the design, detailed analysis and building of prototypes gives DARcorporation a unique advantage over other companies, since we can go from initial design all the way through full size manufacturing. The unique tools developed for design and analysis make DARcorporation the best choice for any new wind turbine development. DARcorporation engineers can advise on what the best materials are for your design and what the best configuration is. We will work with you to design and optimize your wind turbine for performance, manufacturability and cost.
Proposal & Rates
Please Contact Dr. Willem Anemaat for additional information or a detailed proposal. We will need to know your requirements such as design wind speeds, design RPM, type of wind mill, power output required and any other information you can share. We will write a detailed proposal with statement of work, showing tasks, cost and calendar time. This will be provided at no cost or obligation.