labyrinth spillway is an appropriate option to pass pmf discharge. the most advantages of this type of spillway are higher discharge capacity, easy aeration as well as low fluctuations of flow surface. it is essential to find the optimum geometry considering the maximum passing discharge under specific hydraulic conditions with minimum construction cost. in this study, fuzzy inference system (f...

recently the stepped spillways have been used as an appropriate solution for energy dissipation. in the present study, siahbisheh dam spillway is simulated by using computational fluid dynamic (cfd), in which the mixture method and reynolds stresses model (rsm) turbulence model is used. in the first modeling series the over all steppes slope is constant. the number of the steps is increased to ...

Self-sustained instabilities and pseudo-periodic motion may be observed in hydraulic structures and industrial flows. Documented examples include the hydraulic jump, sloshing motion in a reservoir and surging waves in pooled stepped spillways. The instabilities may generate some very large turbulence levels and integral turbulent scales, combining the contributions of both slow fluctuations and...

An experimental study was conducted on a large size stepped spillway model with a moderate slope (26.6o) for a range of discharges between 0.020 and 0.237 m/s. In some experiments, the stepped chute was equipped with uniform steps of 5 and 10 cm heights respectively. In addition several non-uniform configurations with combinations of 5 and 10 cm high steps were investigated. For each configurat...

High nitrogen (N) loading to coastal aquatic systems can be expressed as increased algal production and subsequent low dissolved oxygen. In April, 2008, predictions for extreme flood stage for the Lower Mississippi River triggered the opening of the Bonnet Carré Spillway, a major release valve for the river. The spillway diverted approximately 8 km3 of water over one month of operation into Lak...

Turbo generator shafts are often subjected to cyclic torsion resulting in formation of large longitudinal cracks as well as circumferential cracks. The presence of these cracks could greatly impact the shaft resonance frequencies. In this paper, dynamic response of a shaft with longitudinal and circumferential cracks is investigated through a comprehensive analytical study. The longitudinally c...

in this paper, the effects of transverse cracks on rotating shaft were studied. according to earlier works, crack shaft failure decrease the critical speed of the shaft and also exhibit a nonlinear vibration behaviour leading to increases the amplitude of 1x and 2x harmonics (first and second order of rotational speed in torsional vibration). this suggests that the application of order analysis...