Browsing by Author "Rao, P.S.B."

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An exploratory analysis of rainfall: A case study on western ghats of India
(IEOM Society ieom-society@iieom.org, 2018) Rao, P.S.B.; Shetty, S.; Umesh, P.; Shetty, A.
In this study high resolution 0.250 Ã—0.250 (approximately 25KmÃ—25Km) gridded daily rainfall data is used to analyze the effect of changing climate on distribution of rainfall in different topographical zones of Western Ghats (WG) of India over the period 1901-2013. The non parametric two tailed Mann- Kendall with Hamed and Rao's method of autocorrelation and Sen's slope estimator for obtaining magnitude of change over time period is used. The rainfall trend in annual, monsoon and post-monsoon is increasing in state of Goa and Coastal region of Karnataka state and significantly decreasing in some part of Kerala and Maharashtra state. Winter season rainfall has seen a declined trend in southern part of the study area and in high elevated region of Kerala state. Even the mean rainfall over the study area is declining from 1951-1960 with disturbance in alternate sequence of flood and drought year from period 1990. The frequency of heavy rainfall events (65mm-124.4mm) are increasing in recent decades with 40-50% contribution from 2000-2013 in regions of Maharashtra state. The trend of heavy rainfall events are increasing in West Coast of India at 5% significance level with no trend in very heavy to extreme rainfall events (>124.5mm). Â© IEOM Society International.
An exploratory analysis of rainfall: A case study on western ghats of India
(2018) Rao, P.S.B.; Shetty, S.; Umesh, P.; Shetty, A.
In this study high resolution 0.250 �0.250 (approximately 25Km�25Km) gridded daily rainfall data is used to analyze the effect of changing climate on distribution of rainfall in different topographical zones of Western Ghats (WG) of India over the period 1901-2013. The non parametric two tailed Mann- Kendall with Hamed and Rao's method of autocorrelation and Sen's slope estimator for obtaining magnitude of change over time period is used. The rainfall trend in annual, monsoon and post-monsoon is increasing in state of Goa and Coastal region of Karnataka state and significantly decreasing in some part of Kerala and Maharashtra state. Winter season rainfall has seen a declined trend in southern part of the study area and in high elevated region of Kerala state. Even the mean rainfall over the study area is declining from 1951-1960 with disturbance in alternate sequence of flood and drought year from period 1990. The frequency of heavy rainfall events (65mm-124.4mm) are increasing in recent decades with 40-50% contribution from 2000-2013 in regions of Maharashtra state. The trend of heavy rainfall events are increasing in West Coast of India at 5% significance level with no trend in very heavy to extreme rainfall events (>124.5mm). � IEOM Society International.
Numerical investigation of wave interaction with pile breakwater
(2018) Rao, P.S.B.; Mathew, S.E.; Suvarna, P.; Sathyanarayana, A.H.; Umesh, P.
Pile breakwater consists of a number of piles spaced closely. It works similar to the offshore breakwater by attenuating the energy of the waves and it is due the turbulence caused because of wave-pile interaction. The efficiency of the pile breakwater of single row and two rows is investigated numerically. An open source Computational Fluid Dynamics (CFD) software REEF3D is used in the present study. Initially the grid convergence study is conducted in a rectangular wave flume with a two-dimensional setup and the results are evaluated by comparing the numerical wave profile with the theoretical profile in accordance with the adopted wave theory. The efficiency of the numerically modelled pile breakwater is investigated in terms of the transmission coefficient. The simulations carried out are in accordance with the physical model studies as reported by Subba Rao et al., (1999). The numerically obtained results are validated with the experimental data. The numerically obtained results for the pile breakwater has shown an average of 91.5% agreement with that of experimental results. � IEOM Society International.
Numerical investigation of wave interaction with pile breakwater
(IEOM Society ieom-society@iieom.org, 2018) Rao, P.S.B.; Mathew, S.E.; Suvarna, P.; Hunasanahally Sathyanarayana, A.H.; Umesh, P.
Pile breakwater consists of a number of piles spaced closely. It works similar to the offshore breakwater by attenuating the energy of the waves and it is due the turbulence caused because of wave-pile interaction. The efficiency of the pile breakwater of single row and two rows is investigated numerically. An open source Computational Fluid Dynamics (CFD) software REEF3D is used in the present study. Initially the grid convergence study is conducted in a rectangular wave flume with a two-dimensional setup and the results are evaluated by comparing the numerical wave profile with the theoretical profile in accordance with the adopted wave theory. The efficiency of the numerically modelled pile breakwater is investigated in terms of the transmission coefficient. The simulations carried out are in accordance with the physical model studies as reported by Subba Rao et al., (1999). The numerically obtained results are validated with the experimental data. The numerically obtained results for the pile breakwater has shown an average of 91.5% agreement with that of experimental results. Â© IEOM Society International.