Classical fluid mechanics is a branch of continuum mechanics; that is, it proceeds on the assumption that a fluid is practically continuous and homogeneous in structure. The fundamental property which distinguishes a fluid from other continuous media is that it cannot be in equilibrium in a state of stress such that the mutual action between two adjacent parts is oblique to the common surface. Though this property is the basis of hydrostatics and hydrodynamics, it is by itself insufficient for the description of fluid motion. In order to characterize the physical behavior of a fluid the property must be extended, given suitable analytical form, and introduced into the equations of motion of a general continuous medium, this leading ultimately to a system of differential equations which are to be satisfied by the, velocity, density, pressure, etc. of an arbitrary fluid motion. In this article we shall consider these differential equations, their derivation from fundamental axioms, and the various forms which they take when more or less special assumptions concerning the fluid or the fluid motion are made.

Mathematical Principles of Classical Fluid Mechanics

Predator–prey interactions between swimming animals of the zooplankton are studied in a mathematical model. The assumptions are: 1) the animals are points in a 1-m3 homogeneous space, 2) the animal...

Encounter Probabilities and Community Structure in Zooplankton: a Mathematical Model

This text introduces and draws together pertinent aspects of fluid dynamics, physical oceanography, solid mechanics, and organismal biology to provide a much-needed set of tools for quantitatively examining the biological effects of ocean waves. "Nowhere on earth does water move as violently as on wave-swept coasts, " writes the author, "and every breaker that comes pounding on the shore places large hydrodynamic forces on the organisms resident there." Yet wave-swept coral reefs and rocky shores are home to some of the world's most diverse assemblages of plants and animals, and scientists have chosen these environments to carry out much of the recent experimental work in community structure and population dynamics. Until now these studies have been hampered because biologists often lack a working understanding of the mechanics of the wave-swept shore. Mark Denny here supplies that understanding in clear and vivid language.Included are an introduction to wave-induced water motions and the standard theories for describing them, a broad introduction to the hydrodynamic forces these water movements place on plants and animals, and an explanation of how organisms respond to these forces. These tools are put to use in the final chapters in an examination of the mechanisms of "wave exposure" and an exploration of the mechanical determinants of size and shape in wave-swept environments.

Biology and the Mechanics of the Wave-Swept Environment

This paper presents an analytical model of the cold-spray process. By assuming a one-dimensional isentropic flow and constant gas properties, analytical equations are solved to predict the spray particle velocities. The solutions demonstrate the interaction between the numerous geometric and material properties. The analytical results allow determination of an optimal design for a cold-spray nozzle. The spray particle velocity is determined to be a strong function of the gas properties, particle material density, and size. It is also shown that the system performance is sensitive to the nozzle length, but not sensitive to the nozzle shape. Thus, it is often possible to use one nozzle design for a variety of operational conditions. Many of the results obtained in this article are also directly applicable to other thermal spray processes.

Gas Dynamic Principles of Cold Spray

An experimental and theoretical investigation of low Reynolds number, high subsonic Mach number, compressible gas flow in channels is presented. Nitrogen, helium, and argon gases were used. The channels were microfabricated on silicon wafers and were typically 100 μm wide, 104 μm long, and ranged in depth from 0.5 to 20 μm. The Knudsen number ranged from 10-3 to 0.4. The measured friction factor was in good agreement with theoretical predictions assuming isothermal, locally fully developed, first-order, slip flow.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022112095000358

Gas flow in micro-channels

Partial table of contents: BACKGROUND. Foundations of Fluid Dynamics. Foundations of Thermodynamics. ONE--DIMENSIONAL FLOW. Isentropic Flow. Normal Shock Waves. Flow in Ducts with Heating or Cooling. INTRODUCTION TO FLOW IN TWO AND THREE DIMENSIONS. The Equations of Motion for Steady, Irrotational Flow. SUBSONIC FLOW. Hodograph Method for Two--Dimensional, Subsonic Flow. Three--Dimensional, Subsonic Flow. SUPERSONIC FLOW. Two--Dimensional, Supersonic Flow with Small Perturbations. Oblique Shocks. Appendices. Index.

Ascher H. Shapiro

Papers

Dynamics and thermodynamics of compressible fluid flow

Shape and flow : the fluid dynamics of drag

Shape and Flow