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Roy S.,Indian Institute of Technology Ropar
IEEE Transactions on Sustainable Energy | Year: 2012

The distorted output of a pitch angle controlled (PAC) horizontal axis turbine, as influenced by short duration wind variations like turbulence and gusts, is analyzed under the assumption of two-parameter Weibull statistics. The well accepted concept of turbulence intensity is used as a parametric measure of short duration wind variations. Analytical expressions are formulated and used to estimate the short duration aggregate power output from a turbine, together with the fractional deviations from corresponding ideal zero-turbulence values. Operating conditions of constant turbulence intensity, and constant wind speed standard deviation, are considered separately for the studies. Sensitivity of turbine output power to cut-in and rated values of wind speed are evaluated and discussed. © 2010-2012 IEEE.


Roy S.,Indian Institute of Technology Ropar
IEEE Transactions on Sustainable Energy | Year: 2012

Randomness of wind speed around a short-duration-stable mean value is commonly referred to as short duration wind variation. This paper investigates the effect of substantial wind-based capacity inclusion on optimal load dispatch, with the source wind susceptible to short duration variations. Analytical formulation of the economic load dispatch (ELD) problem inclusive of wind power generation is presented separately for cases with and without representation of transmission losses. In each formulation, the effect of short duration wind variations is included as an aggregate, thereby avoiding the complexity of stochastic models. Three-generator and 20-generator study cases are discussed to illustrate two distinct aspects of the ELD problem. First, the optimal cost, losses, and system-$λ are presented across a range of short-duration-stable mean wind speed. Thereafter, the sensitivity of all three metrics is discussed with reference to different levels of short duration wind variations. © 2012 IEEE.


Tripathi D.,Indian Institute of Technology Ropar
Journal of Bionic Engineering | Year: 2012

A mathematical model is constructed to examine the characteristics of three layered blood flow through the oscillatory cylindrical tube (stenosed arteries). The proposed model basically consists three layers of blood (viscous fluids with different viscosities) named as core layer (red blood cells), intermediate layer (platelets/white blood cells) and peripheral layer (plasma). The analysis was restricted to propagation of small-amplitude harmonic waves, generated due to blood flow whose wave length is larger compared to the radius of the arterial segment. The impacts of viscosity of fluid in peripheral layer and intermediate layer on the interfaces, average flow rate, mechanical efficiency, trapping and reflux are discussed with the help of numerical and computational results. This model is the generalized form of the preceding models. On the basis of present discussion, it is found that the size of intermediate and peripheral layers reduces in expanded region and enhances in contracted region with the increasing viscosity of fluid in peripheral layer, whereas, opposite effect is observed for viscosity of fluid in intermediate layer. Final conclusion is that the average flow rate and mechanical efficiency increase with the increasing viscosity of fluid in both layers, however, the effects of the viscosity of fluid in both layers on trapping and reflux are opposite to each other. © 2012 Jilin University.


Srivastava R.,Indian Institute of Technology Ropar
Journal of Colloid and Interface Science | Year: 2010

A novel and eco-friendly route for the synthesis of porous CeO2 microstructure is reported. The citric acid mediated economical route is developed for the synthesis of a three-dimensional (3D) flowerlike micro/nanocomposite structure. Materials were characterized by a complementary combination of X-ray diffraction (XRD), nitrogen sorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron microscopy (XPS). CeO2 samples obtained have remarkably high surface area when compared to the commercial CeO2 sample. The surface area of CeO2 sample decreased upon calcination at higher temperature. However, the surface area is still almost 20 times more when compared to the commercial CeO2 sample. TEM investigation reveals that upon calcination at higher temperature, the size of the crystal increased but the short range order was merely disturbed. The analyses shows that the present method is suitable as a direct route for synthesizing nanoporous CeO2. Micro/nanocomposite CeO2 was found to be an excellent sorbent for the removal of poisonous pollutants present in water, such as arsenic (As) and chromium (Cr). © 2010 Elsevier Inc.


Roy S.,Indian Institute of Technology Ropar
IEEE Transactions on Energy Conversion | Year: 2013

The inexact power output from a pitch angle-controlled (PAC) horizontal-axis turbine, as influenced by short duration wind variations like turbulence and gusts, has been the subject of well-documented experimental and empirical studies. In this paper, an analytical interpretation of the phenomena is presented under assumption of two-parameter Weibull statistics for short duration wind variations. The popular concept of turbulence intensity is used as a parametric measure for randomness of wind speed. The formulations culminate in analytical expressions for two distinct metrics of power distortion, namely: (a) the short duration output power from the turbine as a mean distinct from corresponding ideal zero-Turbulence value; and (b) the output power variability as a quantification of randomness around the mean. Estimates of both metrics are presented for operating conditions in accordance with the well-known IEC 61400-1 standards. Trends indicated by computed estimates are found to be consistent with empirically observed data from field studies that are reported in the literature. © 1986-2012 IEEE.

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