This paper deals with pump as turbine (PAT) as a feasible solution to the energy problems in rural and hilly areas. PAT provides an economical alternative to actual turbines especially for pico and microhydropower generation. PAT is essentially a pump operating in turbine mode by changing direction of flow and hence the direction of rotation of the impeller. In the forthcoming discussion, an in...

Based on the actual experiment signals of draft tube, the correlation dimension analysis has been carried on using the time domain signals. Through correlation dimension analysis of pressure fluctuating under different load, the results indicate that the pressure fluctuation conditions in draft tube are not same under different load, the corresponding fractal correlation dimensions are also dif...

the water hammer phenomenon in hydroelectric power plant’s penstock is one of the famous troubles which have been an interest for researchers. hence this phenomenon can cause many harmful effects on pipe lines and turbine, it is essential that effects of these surges along with line and turbine have been studied and suitable methods for controlling presented. in this way one of the most effecti...

Francis turbines can experience critical instabilities at high load operating points, limiting their maximum power output. The swirling flow developed in the draft tube produces a cavitating axisymmetric volume, acting as an internal energy source leading to a self-excited surge phenomenon. The pulsation of the vortex rope corresponds to one of the eigenfrequencies of the hydraulic system. Effo...

In this work, the estimation of crack initiation life of a hydraulic Francis turbine runner is presented. The life prediction is based on the local strain approach to predict the initiation life. First, the analysis is carried out in air and in water condition and the runner’s natural frequencies were calculated using the finite element (FE) method. The analysis in air is compared with experime...

A system of vertical drains with combined vacuum and surcharge preloading is an effective solution for promoting radial flow, accelerating consolidation. However, when a mixture of soil and water is deposited at a low initial density, a significant amount of deformation or surface settlement occurs. Therefore, it is necessary to introduce large-strain theory, which has been widely used to manag...

A mathematical physical model for dynamic simulation of flow and temperature in district heating networks (DHN) is proposed. The network structure is described by means of a graph-theoretical approach where the network elements are pipe sections, consumers and heat sources. The governing equations for hydraulic flows and heat distribution through pipe networks are presented. In addition, proper...