유체역학-점성흐름에 대해 설명하시오.

소개글

유체역학-점성흐름에 대해 설명하시오.

목차

5.1 LAMINAR AND TURBULENT FLOWS; INTERNAL AND EXTERNAL FLOWS
5.2 NAVIER-STOKES EQUATIONS
5.3 LAMINAR, INCOMPRESSIBLE, STEADY FLOW BETWEEN PARALLEL PLATES
5.4 LAMINAR FLOW THROUGH CIRCULAR TUBES AND CIRCULAR ANNULI
5.5 TURBULENT SHEAR RELATIONS
5.6. TURBULENT FLOW IN OPEN AND CLOSED CONDUITS
5.8 STEADY INCOMPRESSIBLE FLOW THROUGH SIMPLE PIPE SYSTEMS
5.9 MINOR LOSSES
5.10 LUBRICATION MECHANICS

본문내용

In Chap. 3 the basic equations used in the analysis of fluid-flow situations were discussed. The fluid was considered frictionless, or in some cases losses were assumed or computed without probing into their underlying causes. This chapter deals with real fluids, i.e., situations in which irreversibilities are important. Viscosity is the fluid property that causes shear stresses in a moving fluid; it is also one means by which irreversibilities or losses are developed. In turbulent flows random fluid motions, superposed on the average, create apparent shear stresses that are more important than those due to viscous shear. These topics are the central theme in the chapter. First, the concept of the Reynolds number, introduced in Chap. 4, is developed. The characteristics that distinguish laminar from turbulent flow are presented, and the categorization of flows into internal versus external is established. This chapter concentrates on internal-flow cases. Steady, laminar, incompressible flows are first developed, since the losses can be computed analytically. Resistance to steady, uniform, incompressible, turbulent flow is then examined for open and closed conduits. Free-surface flow in open channels is introduced, followed by an extensive treatment of pipe flow. The chapter closes with a discussion of lubrication mechanics.

5.1 LAMINAR AND TURBULENT FLOWS; INTERNAL AND EXTERNAL FLOWS

The Reynolds Number
Laminar flow is defined as flow in which the fluid moves in layers, or laminas, one layer gliding smoothly over an adjacent layer with only a molecular interchange of momentum. Any tendencies toward instability and turbulence are damped out by viscous shear forces that resist relative motion of adjacent fluid layers. Turbulent flow, however, has very erratic motion of fluid particles, with a violent transverse interchange of momentum. The nature of the flow, i.e., whether laminar or turbulent, and its relative position along a scale indicating the relative importance of turbulent to laminar tendencies are indicated by the Reynolds number. The

참고 자료

없음