National Aerospace Laboratories

About: National Aerospace Laboratories is a facility organization based out in Bengaluru, India. It is known for research contribution in the topics: Coating & Corrosion. The organization has 1838 authors who have published 2349 publications receiving 36888 citations.

The interaction of Indian monsoon depressions with northwesterly midlevel dry intrusions

Abstract: Monsoon depressions (MDs) bring substantial monsoon rainfall to northern and central India. These events usually form over the Bay of Bengal and travel across northern India toward Pakistan. Using European Centre for Medium-Range Weather Forecasts interim reanalysis, an MD-tracking algorithm, and an objective identification method, the authors find that about 40% of MDs interact with northerly intrusions of dry desert air masses as the MDs traverse the subcontinent. MD interactions with dry intrusions are often preceded by positive potential vorticity (PV) anomalies on the subtropical jet and low-level anticyclonic anomalies over the north Arabian Sea. Dry intrusions nearly halve the precipitation rate in the southwest quadrant of MDs, where MDs rain the most. However, dry intrusions increase the rainfall rate near the MD center. Similarly, ascent is reduced west of the MD center and enhanced at the MD center, especially in the upper troposphere. The reduced ascent west of MD centers is likely att...

A new micromechanics approach to the application of Eshelby's equivalent inclusion method in three phase composites with shape memory polymer matrix

Abstract: In the present work Eshelby's equivalent inclusion method is extended to compute the effective properties of two inclusions in a heterogeneous matrix. Generally Eshelby's problem involves a single inclusion under dilute distribution in two phase composites. Moreover, unlike the dual inclusion theory, which is based on the concept of one inclusion embedded in to the second inclusion, alternate problem is now addressed. In this paper Eshelby's single equivalent inclusion concept is extended to the case of composite consisting of two different inclusions embedded separately in a heterogeneous matrix. In the composite, first inclusion is fibre and second inclusion is carbon nanotube embedded in a shape memory polymer heterogeneous matrix. The solution is obtained through individual eigenstrains in both the inclusions. The general closed form relations for the effective moduli and inelastic strain tensors are derived under infinitesimal strains of constituent materials following a two-step homogenization procedure. Analytical solutions of Eshelby's problem with two cylindrical inclusions explicit of each other, having different properties and placed in the same inelastic matrix domain are obtained. The relations are then applied to characterise the shape memory polymer composite. The consistency of the novel relations are established by comparing the results with other micromechanics methods.