Electrical transmission towers are stationed at 350 m intervals and a conducting cable 2 cm in diameter is strung between them. How many wires should each tower carry to ensure structural integrity during a tropical storm? The towers are designed to withstand up to 180 kN of transverse force and during a cyclone, wind can blow up to 200 km/h. Assume there is no interference between the wires and take air density as 1.2 kg/m3 and viscosity as 1.7×10-5 Nsm-2 . If the smooth insulation on the wires is mechanically roughened up before application what effect it will have on the design? Also, establish whether the wires are likely to be subjected to self-induced vibrations and if so what the frequency would be. The frequency of such forced vibration, sometimes called self- induced vibration, may be calculated from an empirical formula due to Vincent Strouhal: fd⁄Uo = 0.198(1 − 19.7⁄Re) 250 < Re < 105

Electrical transmission towers are stationed at 350 m intervals and a conducting cable 2 cm in diameter is strung between them. How many wires should each tower carry to ensure structural integrity during a tropical storm? The towers are designed to withstand up to 180 kN of transverse force and during a cyclone, wind can blow up to 200 km/h. Assume there is no interference between the wires and take air density as 1.2 kg/m3 and viscosity as 1.7×10-5 Nsm-2 . If the smooth insulation on the wires is mechanically roughened up before application what effect it will have on the design? Also, establish whether the wires are likely to be subjected to self-induced vibrations and if so what the frequency would be. The frequency of such forced vibration, sometimes called self- induced vibration, may be calculated from an empirical formula due to Vincent Strouhal: fd⁄Uo = 0.198(1 − 19.7⁄Re) 250 < Re < 105

Power System Analysis and Design (MindTap Course List)

6th Edition

ISBN:9781305632134

Author:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Publisher:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Chapter11: Transient Stability

Section: Chapter Questions

Problem 11.19P

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