DESIGN OF A ROBUST CONTROLLER FOR A SUPERSONIC AIRCRAFT USING H-INFINITY APPROACH

In this paper an H(infinity) optimal, robust flight control system design for a supersonic aircraft has been described. Separate controllers are designed for longitudinal and lateral motions. A general two-degrees-of-freedom controller is proposed, where feedback control is designed for robust performance augmentation, while a series compensator is used to ensure the requisite handling qualities. Three alternative methods to achieve performance robustness have been discussed. The results obtained are very encouraging. It is hoped that this approach will equip the flight control engineers with an alternative to the conventional methods

Transient flows and migration in granular suspensions: key role of Reynolds-like dilatancy

We investigate the transient dynamics of a sheared suspension of neutrally buoyant particles under pressure-imposed conditions, subject to a sudden change in shear rate or external pressure. Discrete Element Method simulations show that, depending on the flow parameters (particle and system size, initial volume fraction), the early stress response of the suspension may strongly differ from the prediction of the Suspension Balance Model based on the steady-state rheology. We show that a two-phase model incorporating the Reynolds-like dilatancy law of Pailha & Pouliquen (2009), which prescribes the dilation rate of the suspension over a strain scale γ 0 , quantitatively captures the suspension dilation/compaction over the whole range of parameters investigated. Together with the Darcy flow induced by the pore pressure gradient during dilation or compaction, this Reynolds-like dilatancy implies that the early stress response of the suspension is nonlocal, with a nonlocal length scale which scales with the particle size and diverges algebraically at jamming. In regions affected by , the stress level is fixed, not by the steady-state rheology, but by the Darcy fluid pressure gradient resulting from the dilation/compaction rate. Our results extend the validity of the Reynolds-like dilatancy flow rule, initially proposed for jammed suspensions, to flowing suspension below φ c , thereby providing a unified framework to describe dilation and shear-induced migration. They pave the way for understanding more complex unsteady flows of dense suspensions, such as impacts, transient avalanches or the impulsive response of shearthickening suspensions

A study on zoonotic tuberculosis in selected rural areas of Bagalkot and Belgaum districts of Karnataka state

The close association of cattle/buffaloes to farmers and their family members is a well-known phenomenon in rural India. Cattle are major contributors to the income for the sustenance of families, and for many landless farmers, often the only source of livelihood. The animals are sheltered under the same roof where the family members sleep, cook and eat. This close proximity of humans to cattle/buffaloes exposes farmers and family members to tuberculosis (TB), especially if they are vulnerable (e.g. malnourished children along with adults, diabetics, people with HIV/AIDS, people with addiction to alcohol, or smokers) . Several studies have examined the risk factors that are associated with TB, such as crowding (slum dwellers), poor living conditions, alcohol, and tobacco . Other studies have found a significant proportion of diabetic patients with coexistent TB. This study examines the spread of TB from animals to humans and its public health significance. To achieve this, selected numbers of cattle/buffaloes were tested for TB and the association with humans and animals was examined. Keywords: Tuberculosis, Zoonotic transmission, Tuberculin antigen, Animal positiv