Distribution of Articles published per year
Total number of journals
CONFERENCE-ARTICLE 5 Reads 0 Citations Complementarity of Wind, Solar and Hydro Resources for Combating Seasonal Power Shortage in Nepal Published: 03 November 2014
The 4th World Sustainability Forum, doi: 10.3390/wsf-4-e018
Power generation, predominantly coming from run-of-river type hydropower plants, has fallen short of demand in Nepal. The shortage is acute during the dry post-monsoon months, when river flows are at their minimum. Huge amount of fossil fuel is used to generate power during shortages. Large hydroelectric projects are under construction, but many natural and man-made factors have delayed their construction by years. A survey of the measured wind speed, incoming solar radiation and river water discharge at various sites in Nepal has been done. Wind and solar energy potentials have been found to be high during the dry season, when hydropower generation is low. River flow, and consequently, the hydropower generation is high during the monsoon season, at which time wind speed and solar radiation are very low. With a well-planned transmission system, wind and solar power could compensate reduced hydropower generation during the seasons with low water flow in rivers. In the short term, installing wind and solar energy technologies- which have short gestation periods- is observed to be the right choice. Such a power system, with wind and solar power complementing hydroelectricity, has the potential to save capital and reduce carbon emissions for Nepal.
PREPRINT 4 Reads 0 Citations Effects of non-universal large scales on conditional structure functions in turbulence Published: 05 August 2009
We report measurements of conditional Eulerian and Lagrangian structure functions in order to assess the effects of non-universal properties of the large scales on the small scales in turbulence. We study a 1m $\times$ 1m $\times$ 1.5m flow between oscillating grids which produces $R_\lambda=285$ while containing regions of nearly homogeneous and highly inhomogeneous turbulence. Large data sets of three-dimensional tracer particle velocities have been collected using stereoscopic high speed cameras with real-time image compression technology. Eulerian and Lagrangian structure functions are measured in both homogeneous and inhomogeneous regions of the flow. We condition the structure functions on the instantaneous large scale velocity or on the grid phase. At all scales, the structure functions depend strongly on the large scale velocity, but are independent of the grid phase. We see clear signatures of inhomogeneity near the oscillating grids, but even in the homogeneous region in the center we see a surprisingly strong dependence on the large scale velocity that remains at all scales. Previous work has shown that similar correlations extend to very high Reynolds numbers. Comprehensive measurements of these effects in a laboratory flow provide a powerful tool for assessing the effects of shear, inhomogeneity and intermittency of the large scales on the small scales in turbulence.