Journal of Energy Engineering

Variable speed generators have recently become available at a reasonable cost. There has been significant interest in applying this technology to hydroturbines, possibly offsetting the need for adjustable blades or gates. Using variable speed turbines to enhance flow control is investigated theoretically and from similitude calculations. Turbine discharge may increase or decrease with rotational speed, depending upon the characteristics of the individual turbine, i.e., specific speed. While the analysis indicates that the variable speed capability does not have a great potential as a flow control mechanism, a turbine designed with the variable speed capability in mind may enhance the performance and range of operation.

Length scale‐down (LS) model tests have been traditionally employed for laboratory studies on aeolian vibration of transmission line conductors. The span adopted is normally 30 m and is recommended by the relevant Indian, as well as other, standards. The traditionally adopted length of the LS model is reexamined herein to establish the rationale behind the choice. Based on the theoretical studies discussed, certain guidelines for the choice of model span of conductor are emphasized. In addition, the adequacy of the LS span as a tool for predicting the performance of the full span is reestablished.

The wind influences the design, construction, and operation of a coal‐fueled power plant in many respects. This presentation explores several design, fabrication, erection, and serviceability problems and practices. Specifically considered are shortcomings of standards with regard to wall panel and fastener design, concerns about fatigue failures at low stress levels and analytical needs for wind‐sensitive structures such as steel stacks and transmission poles, requirements for quality control of materials and fabrication (including welding and galvanizing), and the need for attention to structural details for force transfer. Examples are also drawn from design of generation buildings, coal handling and substation structures; construction of silos, cooling towers, and pond liners; and behavior of chimneys and stacks in both along‐wind and across‐wind directions.