EES 3: Mechanics of Fluids PDF

EES 3: Mechanics of Fluids ENGR. BHONG T. LUCENECIO PLV CE LECTURER EES 3: Mechanics of Fluids 1 – INTRODUCTION TO FLUID MECHANICS & FLUID PROPERTIES I ENGR. BHONG T. LUCENECIO PLV CE LECTURER Introduction to Fluid Mechanics As fut...

EES 3: Mechanics of Fluids ENGR. BHONG T. LUCENECIO PLV CE LECTURER EES 3: Mechanics of Fluids 1 – INTRODUCTION TO FLUID MECHANICS & FLUID PROPERTIES I ENGR. BHONG T. LUCENECIO PLV CE LECTURER Introduction to Fluid Mechanics As future CIVIL ENGINEERS, study of FLUID MECHANICS is very important. Understanding the fluid properties aids to different application in helping to enhance the quality of life in various aspect. Improved Water Management Introduction to Fluid Mechanics As future CIVIL ENGINEERS, study of FLUID MECHANICS is very important. Understanding the fluid properties aids to different application in helping to enhance the quality of life in various aspect. Enhanced Infrastructure Design Introduction to Fluid Mechanics As future CIVIL ENGINEERS, study of FLUID MECHANICS is very important. Understanding the fluid properties aids to different application in helping to enhance the quality of life in various aspect. Effective Environmental Protection Introduction to Fluid Mechanics As future CIVIL ENGINEERS, study of FLUID MECHANICS is very important. Understanding the fluid properties aids to different application in helping to enhance the quality of life in various aspect. Optimized Energy System Introduction to Fluid Mechanics As future CIVIL ENGINEERS, study of FLUID MECHANICS is very important. Understanding the fluid properties aids to different application in helping to enhance the quality of life in various aspect. Advancement in Healthcare Enhanced Transportation Efficient Heating and Cooling Systems Disaster Preparedness Introduction to Fluid Mechanics A branch of mechanics that deals with properties of fluids in different states and their response to forces acting upon them. Fluid Statics - study of fluids at rest. Fluid Dynamics - study of fluids in motion which includes the force exerted upon with relation to velocities and accelerations of the involved fluid. Fluids and its Types Fluids A substance that has no definite shape and will continue to deform or flow whenever an external force is acting upon it. (1)Liquid no definite shape (takes the shape of its container) has definite volume particles are free to move over each other (but still attracted to each other) Fluids and its Types Fluids A substance that has no definite shape and will continue to deform or flow whenever an external force is acting upon it. (2) Gas no definite shape (takes the shape of its container) no definite volume particles move in random motion with little to no attraction to each other. highly compressible Fluids and its Classification Fluids A substance that has no definite shape and will continue to deform or flow whenever an external force is acting upon it. (1)Ideal Fluid assume to have no viscosity incompressible no turbulence when flowing (2) Real Fluid infinite viscosity compressible experiences disturbances Real Fluids Newtonian Fluids no matter what amount of pressure is applied, the viscosity remains constant. Example: water, oil, gasoline, alcohol Real Fluids Non-Newtonian Fluids when pressure is applied, the viscosity of the fluid changes Example: quicksand, oobleck Fluid Properties o Density o Specific Weight Fluid Properties I o Specific Gravity o Compressibility o Viscosity o Surface Tension Fluid Properties II o Capillary Action Fluid Properties I Density also known as volumetric mass density. It is simply its mass per unit volume. Denoted as lower case Greek Less dense Note! substance floats. letter (rho). density mass (kg or slug) volume (m3 or ft3) Note! Denser substance sinks. Fluid Properties I DENSITY FLUID (kg/m3) Alcohol 790 Ammonia 602 Gasoline 720 Glycerin 1,260 Mercury 13,600 Water 1,000 Seawater 1,025 Air 1.2 Oil 800 Fluid Properties I Specific Weight also known as unit weight. It is simply its weight per unit volume. Denoted as Greek letter (gamma). specific weight weight (N or lb) volume (m3 or ft3) Fluid Properties I Specific Weight also known as unit weight. It is simply its weight per unit volume. Denoted as Greek letter (gamma). specific weight weight (N or lb) volume (m3 or ft3) Fluid Properties I Specific Weight also known as unit weight. It is simply its weight per unit volume. Denoted as Greek letter (gamma). specific weight weight (N or lb) volume (m3 or ft3) Fluid Properties I Specific Weight also known as unit weight. It is simply its weight per unit volume. Denoted as Greek letter (gamma). specific weight weight (N or lb) volume (m3 or ft3) Fluid Properties I Specific Volume volume per unit mass. (reciprocal of density) specific volume mass (kg or slug) volume (m3 or ft3) Fluid Properties I Specific Gravity a dimensionless ratio of fluid’s density to some standard reference density. For solids and liquids, the reference is water, and for gases, the reference is air. specific gravity density of fluid density of reference Fluid Properties I Specific Gravity a dimensionless ratio of fluid’s density to some standard reference density. For solids and liquids, the reference is water, and for gases, the reference is air. specific gravity density of fluid density of reference Fluid Properties I Specific Gravity a dimensionless ratio of fluid’s density to some standard reference density. For solids and liquids, the reference is water, and for gases, the reference is air. specific gravity density of fluid density of reference Fluid Properties I Specific Gravity a dimensionless ratio of fluid’s density to some standard reference density. For solids and liquids, the reference is water, and for gases, the reference is air. 𝜸𝒇 𝒔𝒈= 𝜸 𝒓𝒆𝒇 specific gravity 𝜸 𝒇 =𝒔𝒈×𝜸 𝒓𝒆𝒇 density of fluid density of reference Fluid Properties I SPECIFIC FLUID GRAVITY Water 1.00 Seawater 1.03 Oil 0.80 Mercury 13.60 Fluid Properties I Compressibility a measure of how much a substance can decrease in volume under pressure. Its reciprocal is called bulk modulus of elasticity. Denoted as Greek letter (beta) Percent change in volume specific volume change in volume initial volume change in pressure bulk modulus of elasticity Fluid Properties I UNITS OF PRESSURE 1 atm = 101,325 Pascals 1 atm = 1.01325 bar 1 atm = 14.7 psi 1 atm = 760 torr 1 atm = 760 mmHg Fluid Properties I Ideal Gas Law gases are more complicated than liquid. To provide comprehensive and simplified description of the behavior of gases under various condition, they unified the existing gas laws into: density pressure universal gas constant absolute temperature Fluid Properties I Ideal Gas Law gases are more complicated than liquid. To provide comprehensive and simplified description of the behavior of gases under various condition, they unified the existing gas laws into: density pressure universal gas constant absolute temperature Fluid Properties I Ideal Gas Law gases are more complicated than liquid. To provide comprehensive and simplified description of the behavior of gases under various condition, they unified the existing gas laws into: density pressure universal gas constant absolute temperature Fluid Properties I Ideal Gas Law gases are more complicated than liquid. To provide comprehensive and simplified description of the behavior of gases under various condition, they unified the existing gas laws into: (kelvin) density pressure absolute pressure universal gas constant absolute temperature SAMPLE PROBLEM SAMPLE PROBLEM SAMPLE PROBLEM SAMPLE NO c) Liquid Carbon tetrachloride PROBLEM. with a mass of 500 kg is placed in container with 0.325 cubic meter of volume. 1 a) Determine its weight in N. b) Calculate its density in kg/m3. c) Determine its specific weight in N/m3 and kN/m3. d) Calculate its specific gravity. a) d) b) SAMPLE NO Liquid Carbon tetrachloride PROBLEM. with a mass of 500 kg is placed in container with 0.325 cubic meter of volume. 1 a) Determine its weight in N. b) Calculate its density in kg/m3. c) Determine its specific weight in N/m3 and kN/m3. d) Calculate its specific gravity. a) c) d) b) SAMPLE NO Determine the PROBLEM density. 2 of a certain fluid whose specific weight is 95.40 lb/ft3 in kg/m3. SAMPLE NO A reservoir of glycerine PROBLEM. 3has a mass of 1,200 kg and a volume of 0.952 m. Find the 3 following: a) Weight b) b) Mass density c) Unit weight d) a)d) Specific gravity c) SAMPLE NO. Determine the density PROBLEM 4 of the oil if the salad oil has a mass of 73.8 kg and the height of the oil is 0.4 m. *** 𝑟𝑠 0.2 m 0.6 m 0.4 m 0.6 m SAMPLE NO A liquid in a cylinder PROBLEM. which 5 has a volume of 1000 cm at initial pressure of 1 MN/m. If it is 3 2 compressed to a volume of 995 cm3 at pressure of 2 MN/m2. Determine the compressibility and bulk modulus of elasticity of the fluid. SAMPLE NO If the bulk modulus. PROBLEM of 6 elasticity of the water is 2.2 GPa, what pressure is required to reduce its volume by 0.6%? Assume that is no pressure applied initially. or SAMPLE NO Find the mass PROBLEM density.7 of helium at a temperature of 4 degree Celsius and an absolute pressure of 285.92 kPa. Use gas universal constant of 2,079. SAMPLE NO A gas is under an PROBLEM.8 absolute pressure of 21.868 bar at 40 degree Celsius. Determine the following: a) Pressure in kPa. b) Gas constant R (in J/kg-K) if it has a unit a) weight of 362 N/m3. b) SAMPLE NO A certain liquid. PROBLEM is 9 compressed from a volume of 1.25 L with pressure of 175 Pa. If the volume decreases to 1215 cm3 after increasing the pressure by 190 Pa, what is bulk modulus of elasticity of the liquid? For volume:  For Plate No. 1: 1. A specific gasoline weighs 46._ _ 4. If an object has a mass of 2. _ lb/ft3. What is its mass density _ slugs at sea level, what (slug/ft3), specific volume would be its mass at a (ft3/slug), and specific gravity. location where the 2. What pressure (MPa) is required acceleration due to gravity is to reduce the volume by 0.6 _ _ 30 ft/s2? %, Bulk modulus of elasticity of water is 2. _ _ GPa? Also, what is 5. Calculate the specific weight the coefficient of of a liquid if it has an compressibility? absolute pressure of 40. _ _ 3. A gas at 20 degree Celsius and kPa at 20. _ _ degree Celsius. 0.21 absolute has a volume of Use R = 260 J/kg-K. 41 L, and a gas constant of 2 _ _ 6. From no. 5, if the N-m/kg-K. Determine the temperature is brought down density (kg/m3) and the mass of to –100. _ _ degree Celsius, the gas (kg). determine the change in absolute pressure. EES 3: Mechanics of Fluids 1 – INTRODUCTION TO FLUID MECHANICS & FLUID PROPERTIES I UP NEXT!!! 2 – FLUID PROPERTIES II ENGR. BHONG T. LUCENECIO PLV CE LECTURER