Wind Engineering

This paper presents analytical and computational predictions of the performance of an operating 2.5 m long composite wind turbine blade and compares these predictions with the results of detailed measurements. Part 1 of this paper describes in detail the important aspects of the 5 kW wind turbine, the experimental equipment and data acquisition procedures and presents and discusses some of the results from the experimental data. Here the analytical methodology of Eggleston and Stoddard (1987) and the solutions from the computational wind turbine software package Bladed, were used to predict the performance of the blade for a particular set of experimental conditions. The solutions of Eggleston and Stoddard, where only the first order dynamic equations of a simplified blade model are solved, underestimate the root flapwise moment, streamwise blade tip deflection and lead-lag tip deflection, but gave fairly accurate predictions for the blade lead lag moment. The turbine's structural dynamics within Bladed used a more accurate model of the blade and solved the structural dynamic equations by implementing modal analysis. The results gave root flapwise moment of the same order as those determined from the measurements, close agreement with the measured lead-lag moment, a slight underprediction of the flapwise tip deflection and large under prediction of the lead-lag tip deflection. The under prediction of the lead-lag deflection by both methods is likely to be due to the uncoupling of the lead-lag and flapping motions, and the unusual shape of the blade close to its root connection.

Tidal action results in a rise and fall of the sea surface that effectively changes the position of an offshore wind turbine hub in relation to the wind shear profile. This effect is quantified using measured data from three offshore UK sites. Statistical evidence of the influence of tide on mean wind speed and turbulence is presented. The possibilities for improving correlation between onshore and offshore wind data are explored. It is found that improvements in correlation are negligible, even for high tidal range sites.

Roto-dynamic pumps can offer attractive performance when coupled mechanically to wind rotors in shallow lift water pumping applications. However, the gearing ratio required in the transmission for such systems restricts their commercial acceptability. This problem can be reduced by selecting a pump with a very low specific speed, so that, for a particular flow and lift, the shaft need not rotate so fast. Therefore, a regenerative pump was designed and developed for wind powered water pumping applications. A semi-empirical approach was adopted for the design. Performance of the pump was evaluated under variable operating conditions. Power-speed characteristics of the pump at different pumping heads were established and superimposed on those of a suitable wind rotor, to identify the points of operation of the integrated rotor-pump system. With optimum gearing, the peak efficiency points of the rotor and the pump could be reasonably matched over a wide range of conditions. Operating speeds of the system at different wind speeds were estimated and then translated into discharge rates and overall system efficiency. The proposed wind pumping system, with the regenerative pump, performs better on shallow lifts than either wind-driven piston or centrifugal pumping systems.

This paper is an evaluation of potential impacts of a proposed wind farm on property values, tax revenues, and the local economy. The area studied was Kittitas County, (46.59° N, 120.25° W), Washington State, USA, where a combined wind farm of 261 wind turbines, total capacity 390 MW, is proposed. Studies were conducted in that area and regarding similar areas with similar projects. Of particular importance was the visual impact of the windfarm. Details of likely local employment are given (185 full and part-time direct jobs at construction, 85 direct jobs ongoing). Financial modelling considered local and other tax revenues, and associated financial benefits and disbenefits. Studies related to both the time of construction and ongoing operation. Tax revenues from the area would increase by $2.8 million/year (11% increase), of which $693,000/y would be disbursed for immediate local services (2% increase). It was concluded that: there was no evidence for reductions in property values; tax revenues would increase with associated disbursement of benefit within the locality; and associated secondary expenditure in the locality would be significant.

As Denmark and Sweden, the UK is enthusiastically progressing the option of significant power generation from offshore windfarms. This paper reviews, with permission, the UK situation as presented by speakers at a recent conference (reference S868) organised by the UK Institution of Mechanical Engineers. Each section gives a summary, with data, of the presentations by the named speakers. By 2010, offshore windfarms to a total investment of £ 4 billion (6.5 billion Euro) can be expected in UK waters.

William Edward Heronemus, Captain, USN (Ret.), Professor Emeritus, University of Massachusetts at Amherst, born April 16, 1920, died November 2, 2002. This is a memorial record and obituary of a remarkable wind power engineer, Bill Heronemus of the University of Massachusetts and, previously, of the US Navy. The author, a previous student and close colleague, writes personally, with much input and support from other colleagues and previous students. The aim is not only to record research, development and commitment at the early stages of modern wind power, but also to honour an admirable pioneer. Bill Heronemus is credited with foreseeing the 1973 Oil Crisis and thereafter wind power developments that have since been realised, including offshore wind farms. He is also credited with teaching and motivating many students who later became professional of modern wind power development and commerce. The obituary Note has been written from personal knowledge and from many written and verbal communications from colleagues and friends of Bill Heronemus who worked with him at different stages of his life. Details are referenced, with other records kept with the author.