On the theory of SODAR measurement techniques (final reporting on WP1, EU WISE project NNE5-2001-297)
Year: 2003
Type: book
Abstract: The need for alternative means to measure the wind speed for wind energy purposes has increased with \nthe increase of the size of wind turbines. The cost and the technical difficulties for performing wind \nspeed measurements has also increased with the size of the wind turbines, since it is demanded that the \nwind speed has to be measured at the rotor center of the turbine and the size of both the rotor and the \nhub height have grown following the increase in the size of the wind turbines. The SODAR (SOund \nDetection And Ranging) is an alternative to the use of cup anemometers and offers the possibility of \nmeasuring both the wind speed distribution with height and the wind direction. \nAt the same time the SODAR presents a number of serious drawbacks such as the low number of \nmeasurements per time period, the dependence of the ability to measure on the atmospheric conditions \nand the difficulty of measuring at higher wind speeds due to either background noise or the neutral \ncondition of the atmosphere. \nWithin the WISE project (EU project number NNE5-2001-297), a number of work packages have been \ndefined in order to deal with the SODAR. The present report is the result of the work package 1. Within \nthis package the objective has been to present and achieve the following: \n- An accurate theoretic model that describes all the relevant aspects of the interaction of the sound \nbeam with the atmosphere in the level of detail needed for wind energy applications. \n- Understanding of dependence of SODAR performance on hard- and software configuration. \n- Quantification of principal difference between SODAR wind measurement and wind speed \nmeasurements with cup anemometers with regard to power performance measurements. \nThe work associated to the above is described in the work program as follows: \na) Draw up an accurate model of the theoretic background of the SODAR. The necessary depth is \nreached when the influences of various variables in the model on the accuracy of the measurement \nhave been assessed. \nb) Describe the general algorithm SODAR uses for sending the beam and measuring the reflections. \nDescribe the influence of various settings on the working of the algorithm. \nc) Using the data set from work package two analyse the differences between point measurements and \nprofile measurements. \nAll the above issues are addressed in the following report
Language: English
Subfield: Aerospace Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W1591448839