Tropical cyclonic storms – Modeling studies in Indian Air Force

lkj & ns’k esa Hkkjrh; ok;qlsuk ¼vkbZ- ,- ,Q-½ dh lqjf{kr mM+kuksa ds fy, ekSle lsok,¡ miyC/k djkus dk mRrjnkf;Ro ekSle foKku foHkkx ds funs’kky; dk gSA Hkkjrh; ok;qlsuk ds csl ij fLFkr ekSle ¼esV½ dk;kZy; m".kdfVca/kh; pØokrksa ds cuus] rhoz gksus vkSj mudh xfr dk lw{e :Ik ls ekWuhVju djrs gSa rFkk ok;qlsuk dh cgqewY; lEifRr] eq[; :Ik ls gokbZ&tgktksa dh lqj{kk ds fy, psrkouh tkjh djrs gSaA pØokr ds izdksi ls izHkkfor fdlh Hkh LFkku ij cpko dk;ksaZ esa yxs gsyhdkWIVjksa@ok;q;kuksa ds fy, Hkh ;g dk;kZy; ekSle lsok,¡ miyC/k djkrs gSaA ekWMy ij fd, x, v/;;uksa ds vk/kkj ij okLrfod le; iwokZuqeku ds fy, Hkkjrh; ok;qlsuk }kjk 'kks/k dk;Z fd;k tk jgk gSA xzsy vkSj dSu&fÝ’k 2 ¼lrgh laogu lfgr½ diklh izpkyhdj.k ;kstuk dk mi;ksx djds pØokr ds ekxZ ds iwokZuqeku ds fy, Hkkjrh; ok;qlsuk ds ekSle vuqHkkx }kjk mM+hlk ds egkpØokr ds eslksLdsy fun’kZ ,e- ,e- 5 ds vk/kkj ij v/;;u fd;k x;k gSA xzsy ;kstuk ls rwQku ds okLrfod ekxZ ls yxHkx fudV ds ekxZ dk irk pyk gSA dSu&fÝ’k 2 ;kstuk ls irk pys ekxZ ls if’pe caxky vkSj mlds vkl&ikl ds {ks=ksa esa pØokr ds izfrorZu dk irk pyk gSA The Directorate of Meteorology is responsible for the provisioning of weather services for safe conduct of Indian Air Force (IAF) flying operations in the country. The Meteorological (Met) Sections at IAF bases closely monitor a Tropical Cyclone formation, intensification and movement and issue storm warning to safeguard its valuable property that primarily includes Aircrafts. It also provides the weather services for all the helicopter/Aircraft Rescue Operations that are taken up after the fury of the cyclone experienced at a place. Generation of real time forecast from model studies is in the Research Stage in IAF. A meso-scale model (MM5) studies of super cyclone of Orissa were carried out by IAF Met to generate forecast tracks of the Cyclone using Grell and Kain-Fritsch 2 (with shallow convection) cumulus parameterization scheme. The Grell scheme indicated the track slightly close to the actual track of the storm. The KF2 scheme led to the generation of the track that indicated the re-curvature of the system in to West Bengal and adjoining regions.

Download Full-text

A novel synergistic multi-scale modeling framework to predict micro- and meso-scale damage behaviors of 2D triaxially braided composite

International Journal of Damage Mechanics ◽

10.1177/10567895211033974 ◽

2021 ◽

pp. 105678952110339

Author(s):

Hongyong Jiang ◽

Yiru Ren ◽

Qiduo Jin

Keyword(s):

Compressive Load ◽

Scale Model ◽

Modeling Framework ◽

Braided Composite ◽

Multi Scale ◽

Scale Modeling ◽

Bridge Model ◽

Multi Scale Modeling ◽

Transverse Damage ◽

Meso Scale

A novel synergistic multi-scale modeling framework with a coupling of micro- and meso-scale is proposed to predict damage behaviors of 2D-triaxially braided composite (2DTBC). Based on the Bridge model, the internal stress and micro damage of constituent materials are respectively coupled with the stress and damage of tow. The initial effective elastic properties of tow (IEEP) used as the predefined data are estimated by micro-mechanics models. Due to in-situ effects, stress concentration factor (SCF) is considered in the micro matrix, exhibiting progressive damage accumulation. Comparisons of IEEP and strengths between the Bridge and Chamis’ theory are conducted to validate the values of IEEP and SCF. Based on the representative volume element (RVE), the macro properties and damage modes of 2DTBC are predicted to be consistent with available experiments and meso-scale simulation. Both axial and transverse damage mechanisms of 2DTBC under tensile or compressive load are revealed. Micro fiber and matrix damage accumulations have significant effects on the meso-scale axial and transverse damage of tows due to multi-scale coupling effects. Different from existing meso-/multi-scale models, the proposed multi-scale model can capture a crucial phenomenon that the transverse damage of tow is vulnerable to micro fiber fracture. The proposed multi-scale framework provides a robust tool for future systematic studies on constituent materials level to larger-scale aeronautical materials.

Download Full-text

A Comparative Evaluation of a Mesoscale Model and Atmospheric Global Circulation Model for Air Quality Simulation: A Multiscale, Multisite Evaluation

ISRN Meteorology ◽

10.5402/2012/826074 ◽

2012 ◽

Vol 2012 ◽

pp. 1-15 ◽

Cited By ~ 2

Author(s):

P. Goswami ◽

J. Baruah

Keyword(s):

High Resolution ◽

Mesoscale Model ◽

Large City ◽

Circulation Model ◽

Urban Pollution ◽

Atmospheric Pollutants ◽

Scale Model ◽

Global Circulation Model ◽

Global Circulation ◽

Meso Scale

Concentrations of atmospheric pollutants are strongly influenced by meteorological parameters like rainfall, relative humidity and wind advection. Thus accurate specifications of the meteorological fields, and their effects on pollutants, are critical requirements for successful modelling of air pollution. In terms of their applications, pollutant concentration models can be used in different ways; in one, short term high resolution forecasts are generated to predict and manage urban pollution. Another application of dynamical pollution models is to generate outlook for a given airbasin, such as over a large city. An important question is application-specific model configuration for the meteorological simulations. While a meso-scale model provides a high-resolution configuration, a global model allows better simulation of large-sale fields through its global environment. Our objective is to comparatively evaluate a meso-scale atmospheric model (MM5) and atmospheric global circulation model (AGCM) in simulating different species of pollutants over different airbasins. In this study we consider four locations: ITO (Central Delhi), Sirifort (South Delhi), Bandra (Mumbai) and Karve Road (Pune). The results show that both the model configurations provide comparable skills in simulation of monthly and annual loads, although the skill of the meso-scale model is somewhat higher, especially at shorter time scales.

Download Full-text