Fundamentals of Fluid Mechanics, 5/E by Bruce Munson, Donald Young, and Theodore Okiishi Copyright © 2005 by John Wiley & Sons, Inc. All rights reserved. Characteristics of Fluids Solid- densely spaced molecules with large intermolecular cohesive forces to maintain its shape. Liquid-molecules are spaced apart ( mm), intermolecular forces are smaller, more freedom in movement.

Fundamentals of Fluid Mechanics, 5/E by Bruce Munson, Donald Young, and Theodore Okiishi Copyright © 2005 by John Wiley & Sons, Inc. All rights reserved. Forces on Surface Fluid- Deforms continuously when acted on by shearing stress (tangential force) (force/unit area)

Fundamentals of Fluid Mechanics, 5/E by Bruce Munson, Donald Young, and Theodore Okiishi Copyright © 2005 by John Wiley & Sons, Inc. All rights reserved. Dimensions Primary Quantities- L, T, M,  Secondary Quantities- Area, Velocity, Density Dimensionally homogeneous Force, F=mass x acceleration = MLT -2 M=FL -1 T 2 Stress= Force/area=  MLT -2 /L 2 =ML -1 T -2 Equation for free falling bodies, d=gt 2 /2; g=32.2 ft/s 2

Fundamentals of Fluid Mechanics, 5/E by Bruce Munson, Donald Young, and Theodore Okiishi Copyright © 2005 by John Wiley & Sons, Inc. All rights reserved. Table 1.1 (p. 4) Dimensions Associated with Common Physical Quantities (continued on next slide)

Fundamentals of Fluid Mechanics, 5/E by Bruce Munson, Donald Young, and Theodore Okiishi Copyright © 2005 by John Wiley & Sons, Inc. All rights reserved. Table 1.1 (p. 4) continued

Fundamentals of Fluid Mechanics, 5/E by Bruce Munson, Donald Young, and Theodore Okiishi Copyright © 2005 by John Wiley & Sons, Inc. All rights reserved. Units British Gravitational System/English system- length (ft), time (s), force (lb), temp ( o F, o R), mass (slug), weight (force due to gravity=mg), g= ft/s 2, i.e., mass of 1 slug weighs 32.3 lb under standard gravity. International System (SI) or metric system - length (m), time (s), temp (K, o C), mass (kg), force (N), g=9.81 m/s 2, Work done, 1 J = 1 N. m; Power (watt) 1 W= 1 J/s =1 N. m/s English Engineering (EE) system- length (ft), time (s), force (lb), temp ( o R), mass (lbm), force (lb), g=9.81 m/s 2, Newton’s second law is expressed as F =ma/g c g c = ft/s 2 ; Weight, W= mg/g c 1 slug = lbm

Fundamentals of Fluid Mechanics, 5/E by Bruce Munson, Donald Young, and Theodore Okiishi Copyright © 2005 by John Wiley & Sons, Inc. All rights reserved. Mass vs. Weight

Fundamentals of Fluid Mechanics, 5/E by Bruce Munson, Donald Young, and Theodore Okiishi Copyright © 2005 by John Wiley & Sons, Inc. All rights reserved. Table 1.2 (p. 7) Prefixes for SI Units

Fundamentals of Fluid Mechanics, 5/E by Bruce Munson, Donald Young, and Theodore Okiishi Copyright © 2005 by John Wiley & Sons, Inc. All rights reserved. Table 1.3 (back cover) Conversion Factors from BG and EE Units to SI Units

Fundamentals of Fluid Mechanics, 5/E by Bruce Munson, Donald Young, and Theodore Okiishi Copyright © 2005 by John Wiley & Sons, Inc. All rights reserved. Table 1.4 (back cover) Prefixes for SI Units

Fundamentals of Fluid Mechanics, 5/E by Bruce Munson, Donald Young, and Theodore Okiishi Copyright © 2005 by John Wiley & Sons, Inc. All rights reserved. A tank of water of total mass of 36 kg rests on the floor of an elevator. Determine the force (in newtons) that the tank exerts on the floor when the elevator is accelerating upward at 7 ft/s 2.

Fundamentals of Fluid Mechanics, 5/E by Bruce Munson, Donald Young, and Theodore Okiishi Copyright © 2005 by John Wiley & Sons, Inc. All rights reserved. Analysis of Fluid Behavior Newton’s laws of motion Conservation of mass First and second laws of thermodynamics Fluid at rest- fluid statics Fluid is moving- fluid dynamics

Fundamentals of Fluid Mechanics, 5/E by Bruce Munson, Donald Young, and Theodore Okiishi Copyright © 2005 by John Wiley & Sons, Inc. All rights reserved. Continuum Matter is made up of atoms that are widely spaced in gas phase Yet, disregard the atomic nature and view it is a continuous, homogeneous matter Treat properties as point functions and assume property vary continuously

Fundamentals of Fluid Mechanics, 5/E by Bruce Munson, Donald Young, and Theodore Okiishi Copyright © 2005 by John Wiley & Sons, Inc. All rights reserved. Density Density,  mass/unit volume –Slugs/ft 3 ; kg/m 3 Specific volume, Specific weight= weight/volume Specific Gravity = density of the fluid/density of water

Fundamentals of Fluid Mechanics, 5/E by Bruce Munson, Donald Young, and Theodore Okiishi Copyright © 2005 by John Wiley & Sons, Inc. All rights reserved. Figure 1.1 (p. 10) Density of water as a function of temperature.

Fundamentals of Fluid Mechanics, 5/E by Bruce Munson, Donald Young, and Theodore Okiishi Copyright © 2005 by John Wiley & Sons, Inc. All rights reserved. Table 1.5 (front cover) Approximate Physical Properties of Some Common Liquids (BG Units)

Fundamentals of Fluid Mechanics, 5/E by Bruce Munson, Donald Young, and Theodore Okiishi Copyright © 2005 by John Wiley & Sons, Inc. All rights reserved. Table 1.6 (front cover) Approximate Physical Properties of Some Common Liquids (SI Units)

Fundamentals of Fluid Mechanics, 5/E by Bruce Munson, Donald Young, and Theodore Okiishi Copyright © 2005 by John Wiley & Sons, Inc. All rights reserved. Ideal/Perfect Gas Law Gases are highly compressible, gas density changes with pressure and temperature, Pressure should be expressed in lb/ft 2 (psf) ; lb/in 2 (psi); N/m 2 (Pa) Standard sea-level atmospheric pressure – 14.7 psi; kPa R is the universal gas constant =8.314 kJ/Kmol ; Btu /lb mol

Fundamentals of Fluid Mechanics, 5/E by Bruce Munson, Donald Young, and Theodore Okiishi Copyright © 2005 by John Wiley & Sons, Inc. All rights reserved. Determine the density, specific gravity and mass of the air in a room whose dimensions are 4 m x 5 m x 6 m at 100 kPa and 25 C