Nature Of Surge Research Articles

A Parametric Investigation of Geometric Variation on Fluid Dynamic Instabilities in Axial Compression Systems

The ability to predict the nature of instabilities is highly important from the compressor design point of view since their consequences could result in widely varying difficulties with the fluid dynamic performance of the systems. Even though the behavior of surge and rotating stall is reported in many literatures, it is noticed that an in-depth analysis is not undertaken. Hence in view of the importance for a deeper understanding, the present paper is aimed at tracking the chaos of these instabilities in a more detailed manner. Primarily the influence of geometric parameters on the nature of surge and rotating stall is investigated. The effect of each of the major geometric parameters such as compressor effective length, annulus area, and plenum volume is discussed. The physical reason for the onset of instabilities is also explained in each case, and the well-accepted Moore-Greitzer model has been used for the present study. The combined effect of physical parameters is determined through the Greitzer <svg style="vertical-align:-0.0pt;width:10.6125px;" id="M1" height="11.175" version="1.1" viewBox="0 0 10.6125 11.175" width="10.6125" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg"> <g transform="matrix(.017,-0,0,-.017,.062,11.113)"><path id="x1D435" d="M594 511q0 -122 -171 -157l1 -2q158 -33 158 -159q0 -52 -34.5 -95t-90.5 -65q-76 -33 -217 -33h-223l8 28q63 5 79.5 19t26.5 72l83 426q9 48 -2.5 60t-77.5 17l6 28h259q195 0 195 -139zM499 509q0 59 -37 83t-91 24q-36 0 -51 -9q-17 -9 -22 -44l-35 -195h62&#xA;q82 0 128 37t46 104zM481 199q0 71 -48 102.5t-121 31.5h-56l-37 -201q-11 -58 7.5 -77t80.5 -19q76 0 125 44.5t49 118.5z" /></g> </svg> parameter. The results shown in this paper clearly elucidate the dominating effect of the geometric parameters on the development of flow instabilities like rotating stall and surge and hence can serve as a design guideline to avoid such instabilities.

The East Coast and London tidal flood warning systems

Disastrous tidal flooding on the East Coast of England in 1953 was followed by the setting up of a flood warning system for the East Coast, and led to consideration being given to the feasibility of excluding dangerous surges from London by the construction of a tidal barrier across the Thames. Frequency estimates in connexion with the latter led in turn to the introduction of an improved warning system for London in 1968. This paper describes the physical setting and the nature of surges on the East Coast and in the Thames estuary, and the means used to forecast them; and refers to supporting investigational work. It discusses the means of disseminating warnings to those at risk and concludes by attempting to foresee how the system might develop.

Lightning Investigation on New England Power Company System

An analysis of the surges recorded during 1927 on a 75-mi. 110-kv. double-circuit transmission line of the New England Power System is presented in this paper. The surges are classified according to cause of surge-voltage damping, extent, etc. General conclusions are drawn regarding the nature of surges and protection afforded by ground wires.

Lightning investigation on New England: Power company system

An analysis of the surges recorded during 1927 on a 75-mi. 110-kv. double-circuit transmission line of the New England Power System is presented in this paper. The surges are classified according to cause of surge-voltage damping, extent, etc. General conclusions are drawn regarding the nature of surges and protection afforded by ground wires.