# Fluid Mechanics

## The study of fluids - liquids and gases. Involves velocity, pressure, density and temperature as functions of space and time

### Absolute or Dynamic Viscosity Online Converter

Convert between dynamic or absolute viscosity units - Poiseuille, Poise, centPoise and more

### Absolute, Dynamic and Kinematic Viscosity

Dynamic, absolute and kinematic viscosities - convert between *CentiStokes (cSt), centipoises (cP), Saybolt Universal Seconds (SSU) and degree Engler*

### Acetone - Density and Specific Weight

Online calculator, figures and tables showing density and specific weight of acetone at temperatures ranging from -95 to 275 °C (-138 to 530 °F) at atmospheric and higher pressure - Imperial and SI Units

### Acetone - Thermophysical Properties

Chemical, physical and thermal properties of acetone, also called 2-propanone, dimethyl ketone and pyroacetic acid. Phase diagram included.

### Air - Altitude, Density and Specific Volume

Density and the specific volume of air vary with elevation above sea level

### Air - Composition and Molecular Weight

Dry air is a mechanical mixture of nitrogen, oxygen, argon and several other gases in minor amounts

### Air - Density at varying pressure and constant temperatures

Figures and tables showing changes in air density at pressure varying from 1 to 10 000 bara (14.5 - 145000 psi) and constant, selected temperatures. Figures are given in different scales.

### Air - Density, Specific Weight and Thermal Expansion Coefficient at Varying Temperature and Constant Pressures

Online calculator, figures and tables showing density, specific weight and thermal expansion coefficient of air at temperatures ranging -100 to 1600 °C (-140 to 2900 °F) at atmospheric and higher pressure - Imperial and SI Units

### Air - Diffusion Coefficients of Gases in Excess of Air

Diffusion coefficients, D_{12}, for gases in large excess of air at temperature varying from 0 - 400 °C

### Air - Dynamic and Kinematic Viscosity

Online calculator, figures and tables showing dynamic (absolute) and kinematic viscosity of air at temperatures ranging from -100 to 1600°C (-150 to 2900°F) at pressure ranging from 1 to 10 000 bara (14.5 - 145000 psia) - SI and Imperial Units

### Air - Molecular Weight and Composition

Dry air is a mixture of gases where the average molecular weight (or molar mass) can be calculated by adding the weight of each component

### Air - Prandtl Number

Figures and table showing changes in Prandtl number for air with changes in temperature and pressure

### Air - Properties at Gas-Liquid Equilibrium Conditions

Figures and tables showing how the properties of air changes along the boiling and condensation curves (temperature and pressure between triple point and critical point conditions). An air phase diagram are also given.

### Air - Specific Heat at Constant Pressure and Varying Temperature

Online calculator, figures and tables showing how specific heat (Cp and Cv) of dry air vary with temperature at different pressures, SI and imperial units

### Air - Specific Heat at Constant Temperature and Varying Pressure

Figures and table showing isobaric (Cp) and isochoric (Cv) specific heat of air at constant temperature and varying pressure ranging 0.01 to 10000 bara

### Air - Thermal Conductivity

Online calculator, figures and tables showing air thermal conductivity at varying temperature and pressure, SI and imperial units.

### Air - Thermal Diffusivity

Figures and tables showing dry air thermal diffusivity at varying temperarure and pressure, SI and Imperial units

### Air - Thermophysical Properties

Thermal properties of air - density, viscosity, critical temperature and pressure, triple point, enthalpi and entropi, thermal conductivity and diffusicity, and more

### Air Duct Components and Minor Loss Coefficients

Minor loss - pressure or head loss - coefficients for air duct distribution systems components

### Ammonia - Density at Varying Temperature and Pressure

Online calculator, figures and tables showing density and specific weight of ammonia at temperatures ranging -50 to 425 °C (-50 to 800 °F) at atmospheric and higher pressure - Imperial and SI Units

### Ammonia - Dynamic and Kinematic Viscosity

Online calculator, figures and tables showing dynamic (absolute) and kinematic viscosity of gasous and liquid ammonia at temperatures ranging from -73 to 425°C (-100 to 800°F) at pressure ranging from 1 to 1000 bara (14.5 - 14500 psia) - SI and Imperial Units

### Ammonia - Prandtl Number

Figures and table showing changes in Prandtl number for ammonia with changes in temperature and pressure

### Ammonia - Properties at Gas-Liquid Equilibrium Conditions

Figures and tables showing how the properties of liquid and gaseous ammonia changes along the boiling/condensation curve (temperature and pressure between triple point and critical point conditions). An ammonia phase diagram are included.

### Ammonia - Specific heat (heat capacity) at varying temperature and pressure

Online calculator, figures and tables showing specific heat (heat capacity), C_{P} and C_{V}, of gasous and liquid ammonia at temperatures ranging from -73 to 425°C (-100 to 800°F) at pressure ranging from 1 to 100 bara (14.5 - 1450 psia) - SI and Imperial Units

### Ammonia - Thermal Conductivity at Varying Temperature and Pressure

Online calculator, figures and tables showing thermal conductivity of liquid and gaseous ammonia at temperatures ranging -70 to 425 °C (-100 to 800 °F) at atmospheric and higher pressure - Imperial and SI Units

### Ammonia - Thermophysical Properties

Chemical, Physical and Thermal Properties of Ammonia. Phase diagram included.

### Archimedes' Law

Forces acting on a body submerged in a fluid

### Average boiling point

Definition, explanation and examples of calculation of various types of average boiling point of petroleum products and other mixtures of hydrocarbons: VABP, MABP, WABP, CABP and MeABP

### Average boiling point from gravity and molecular weight

Formulas and examples of calculation of boiling point of hydrocarbon mixtures from gravity and molecular weight

### Baumé's Hydrometer

Degree Baumé converted to Specific Gravity

### Bernoulli Equation

Conservation of energy - non-viscous, incompressible fluid in steady flow

### Bulk Modulus and Fluid Elasticity

Introduction to - and definition of - Bulk Modulus Elasticity commonly used to characterize compressibility of fluids

### Buoyancy

The resultant force acting on a submerged body

### Capillarity

Capillarity - or capillary action - is the ability of a narrow tube to draw a liquid upwards against the force of gravity

### Carbon dioxide - Density and Specific Weight

Online calculator, figures and tables showing density and specific weight of carbon dioxide, CO_{2}, at temperatures ranging from -50 to 775 °C (-50 to 1400 °F) at atmospheric and higher pressure - Imperial and SI Units

### Carbon dioxide - Prandtl Number

Figures and table showing changes in Prandtl number for carbon dioxide with changes in temperature and pressure

### Carbon dioxide - Thermal Conductivity

Online calculator, figures and table showing thermal conductivity of carbon dioxide, CO_{2}, at temperatures ranging from -50 to 775 °C (-50 to 1400 °F) at atmospheric and higher pressure - Imperial and SI Units

### Carbon Dioxide - Thermophysical Properties

Chemical, physical and thermal properties of carbon dioxide. Phase diagram included.

### Carbon Dioxide Concentrations in Rooms with People

The carbon dioxide concentration in a room can indicate air quality and ventilation system efficiency

### Cauchy Number

Introduction to the Cauchy Number

### Cavitation - an Introduction

Cavitation occurs in fluid flow systems where the local static pressure is below vapor pressure

### Cavitation Number

An introduction to and a definition of the Cavitation Number

### Center of Gravity - Center of Buoyancy

Stability - center of gravity and center of buoyancy

### Chezy Equation

Conduits flow and mean velocity - the Chezy equation

### Colebrook Equation

Calculate friction loss coefficients in pipes, tubes and ducts

### Compressible Gas Flow - Entropy

Calculating entropy in compressible gas flow

### Compression and Expansion of Gases

Isothermal and isentropic gas compression and expansion processes

### Conservation of Mass

The Law of Conservation of Mass states that mass can neither be created or destroyed

### Darcy-Weisbach Pressure and Head Loss Equation

The Darcy-Weisbach equation can be used to calculate pressure or head loss due to friction in ducts, pipes or tubes

### Density of Liquids versus change in Pressure and Temperature

Density and specific volume of a liquid versus change in pressure and temperature

### Density, Specific Weight and Specific Gravity

An introduction to density, specific gravity and specific weight - formulas with examples

### Drag Coefficient

The drag coefficient of an object in a moving fluid influence drag force

### Dynamic or Absolute Viscosity Converting Chart

Dynamic viscosity converting chart with units like *Poiseuille - Poise - centiPoise and more*

### Dynamic Pressure

Dynamic pressure is the kinetic energy per unit volume of a fluid

### Dynamic Viscosity of common Liquids

Absolute - dynamic - viscosity for some common fluids

### Energy and Hydraulic Grade Line

The hydraulic grade and the energy line are graphical presentations of the Bernoulli equation

### Entrance Length and Developed Flow

The entrance length is the length in a tube or duct after an obstruction - until the flow velocity profile is fully developed

### Equation of Continuity

The Equation of Continuity is a statement of mass conservation

### Equations in Fluid Mechanics

Commonly used equations in fluid mechanics - Bernoulli, conservation of energy, conservation of mass, pressure, Navier-Stokes, ideal gas law, Euler equations, Laplace equations, Darcy-Weisbach Equation and more

### Equivalent Diameter

Convert rectangular and oval duct geometry to a equivalent circular diameter - online calculator with imperial and SI-units

### Ethanol - Specific Heat (Heat Capacity), C_{p} and C_{v}

Online calculators, figures and tables showing specific heat (heat capacity), Cp and Cv, of gasous and liquid ethanol at temperatures ranging from -25 to 325 °C (-10 to 620 °F) at atmospheric and higher pressure - Imperial and SI Units

### Ethanol - Thermophysical properties

Chemical, physical and thermal properties of ethanol (also called alcohol or ethyl alcohol). Phase diagram included.

### Euler Equations

The behavior of ideal compressible gas can be described with Euler equations

### Euler Number

Introduction to the Euler Number used in fluid mechanics

### Flow Coefficient *C*_{v} versus Flow Factor *K*_{v}

_{v}

_{v}

Comparing flow coefficient *C _{v}* and flow factor

*K*

_{v}

### Flow of Liquids from Containers - Volume Flow and Emptying Time Calculator

Liquid velocity, volume flow and draining time when emptying containers

### Flow Section Channels - Geometric Relationships

Geometric relationships in flow channels - area, wetted perimeter and hydraulic diameter

### Fluid Mechanics - Imperial and SI Units Dimensions

Imperial (USCS) and SI dimensions and units terminology in fluid mechanics

### Friction Coefficient with Laminar Flow

Laminar flow and friction coefficient

### Froude Number

Introduction to the Froude Number

### Gas Mixtures and Properties

Special care must be taken for gas mixtures when using the ideal gas law, calculating the mass, the individual gas constant or the density

### Hazen-Williams Coefficients

Hazen-Williams coefficients for piping materials

### Hazen-Williams Equation - calculating Head Loss in Water Pipes

Friction head loss (*ft _{H2O} per 100 ft pipe*) in water pipes can be estimated with the empirical Hazen-Williams equation

### Hot Water Heating Systems - Steel Pipes Pressure Loss Chart

Steel pipes in hot water heating systems - pressure loss diagram

### Hydraulic Diameter

Hydraulic diameter of pipes and ducts

### Hydrogen sulfide - Thermophysical Properties

Chemical, physical and thermal properties of hydrogen sulfide, H_{2}S, also called hydrosulfuric acid, sewer gas and stink damp. Phase diagram included.

### Hydrostatic Force acting on a Submerged Surface

A thrust force will act on a submerged surface

### Hydrostatic Pressure

Depth and hydrostatic pressure

### Ideal Gas Law

The relations between volume, pressure, temperature and quantity of a gas, including definition of density of a gas.

### Isentropic Flow

Constant entropy flow is called isentropic flow

### Jet Discharge Propulsion

Propulsive force or thrust induced by an incompressible jet flow

### Kinematic Viscosity - Online Converter

Convert between different kinematic viscosity units - centistokes, poise, lentor and more

### Kinematic Viscosity Conversion Diagram

Convert between Centistokes, Saybolt and Redwood seconds

### Laminar, Transitional or Turbulent Flow

When calculating heat transfer or pressure and head loss it is important to know if a fluid flow is laminar, transitional or turbulent

### Laplace Equation

The Laplace equation is important in fluid dynamics describing the behavior of gravitational and fluid potentials

### Lift and Drag

Body - like an airfoil - in fluid flow

### Liquid ammonia - Thermal Properties at saturation pressure

Density, specific heat, thermal conductivity, viscosity and Prandtls no. of liquid ammonia at its saturation pressure

### Liquids - Kinematic Viscosities

Kinematic viscosities of common liquids like motor oil, diesel fuel, peanut oil and many more

### Mach Number

Introduction to the Mach Number

### Major loss in Ducts, Tubes and Pipes

Major loss - head loss or pressure loss - due to friction in ducts, pipes and tubes

### Major Loss Online Calculator - the Darcy-Weisbach Friction Loss Equation

An online major loss calculator based on the Darcy-Weisbach friction loss equation. Energy (or head) loss is expressed in length units

### Manning's Formula for Gravity Flow

Open channel slope area flow metering

### Manning's Roughness Coefficients

Manning's roughness coefficients for common materials

### Mass and Weight

Mass and Weight - the Gravity Force

### Mechanical Energy and Bernoulli Equation

The mechanical energy equation related to energy per unit mass, energy per unit volume and energy per unit weight involving head

### Melting and Boiling Point, Density and Solubility in Water for Inorganic Compounds

Physical constants for more than 280 common inorganic compounds. Density is given for the actual state at 25°C and for liquid phase at melting point temperature.

### Methane - Density and Specific Weight

Online calculator, figures and tables showing density and specific weight of methane, CH_{4}, at temperatures ranging from -160 to 725 °C (-260 to 1300 °F) at atmospheric and higher pressure - Imperial and SI Units

### Methane - Prandtl number

Figures and table showing changes in Prandtl number for methane with changes in temperature and pressure

### Methane - Thermal Conductivity

Online calculator, figures and table showing thermal conductivity of methane, CH_{4}, at temperatures ranging from -160 to 725 °C (-260 to 1300 °F) at atmospheric and higher pressure - Imperial and SI Units

### Methane - Thermophysical Properties

Chemical, Physical and Thermal Properties of Methane - *CH _{4}*. Phase diagram included.

### Methanol - Thermophysical Properties

Chemical, physical and thermal properties of methanol, CH_{3}OH (also called carbinol, wood alcohol, hydroxy methyl and methyl alcohol). Phase diagram included.

### Minor Loss Coefficients in Pipes and Tubes Components

Minor loss coefficients for common used components in pipe and tube systems

### Minor Loss in Pipe or Duct Components

Minor loss, pressure or head loss in pipe, tube and duct system components

### Mixing Fluids

Final mass and temperature when mixing fluids

### Mixtures, Solutions and Suspensions

The difference between mixtures, solutions and suspensions

### Molecular weight from average boiling point and gravity

Formula and examples of calculation of average molecular weight of hydrocarbon mixtures from gravity and average boiling point, achieved from distillation data.

### Moody Diagram

A Moody diagram that can be used to estimate friction coefficients

### Moody Friction Flow Factor

Online Moody friction flow factor calculator - as used in the Darcy-Weisbach major loss equation

### Motor Oils - Dynamic Viscosity

Dynamic viscosities for motor oils SAE 10 to 50 - temperature range 0 - 100 deg C

### Navier-Stokes Equations

The Navier-Stokes equations are the fundamental partial differentials equations used to describe incompressible fluid flows

### Non-ideal gas - Van der Waals equation and constants

Listing of van der Waals constants for more than 200 gases, used to correct for non-ideal behavior of gases caused by intermolecular forces and the volume occupied by the gas particles

### Nozzles

Gas flow through nozzles - sonic chokes

### Oil Viscosity - Convert Values

Convert between common oil viscosity units

### Orifice, Nozzle and Venturi Flow Rate Meters

The orifice, nozzle and venturi flow rate meters use the Bernoulli Equation to calculate fluid flow rate using pressure difference through obstructions in the flow

### Pascal's Laws

Pascal's laws relates to pressures in fluids

### Pipes - in Series or Parallel

Pressure loss in pipes connected in series or parallel

### Pipes and Fluid Flow Velocities

Calculate fluid flow and pipe velocities in pipes and tubes

### Poiseuille's Formula

The volume flow discharged through a smooth-walled circular pipe

### Prandtl Number

The Prandtl Number is a dimensionless number approximating the ratio of momentum diffusivity to thermal diffusivity

### Pressure

Introduction to pressure - *psi* and *Pa* - online pressure units converter

### Pressure Coefficient

The ratio of pressure forces to inertial forces

### Pressure Energy

Pressure energy in a incompressible fluid

### Pressure Gradient Diagrams

A pressure gradient diagram is a graphical presentation of the static pressure throughout a fluid flow system

### Pressure Units - Online Converter

Convert between pressure units like *Pa, bar, atmosphere, pound square feet, psi and more*

### Pump Affinity Laws

Turbo machines affinity laws can be used to calculate volume capacity, head or power consumption in centrifugal pumps with changing speed or wheel diameters

### Pumps, Compressors, Blowers and Fans

Comparing pumps, compressors, blowers and fans

### Ratios of Specific Heat of Gases

Ratios of specific heat for gases in constant pressure and volume processes

### Reynolds Number

Introduction and definition of the dimensionless Reynolds Number - online calculators

### Solubility

A measure of the maximum amount of a solute that can be dissolved in a solvent

### Solubility guidelines for ionic compounds in water

Guidelines or solubility rules to predict whether or not a given ionic compound is soluble in water at room temperature

### Solubility product constants

The equilibrium constant, Ksp, for aqueous solutions of ionic compounds at 25°C.

### Specific Work of Turbo Machines - Pumps, Compressors and Fans

Specific work from pumps, fans, compressors and turbines

### Speed of Sound Formulas

Calculation formulas for velocity of sound - sonic velocity - in gases, fluids or solids

### Speed of Sound in Water

Speed of sound in water at temperatures ranging *32 - 212 ^{o}F (0 - 100^{o}C)* - Imperial and SI units

### Static Pressure or Head in Fluids

Static pressure and pressure head

### Stokes' Formula

The force of viscosity acting on a smooth sphere

### Strouhal Number

Introduction to the Strouhal Number

### Surface Tension

Surface tension of liquids like water, mercury, oils and more

### Technical Terms in Fluid Mechanics

Some of the most commonly used technical terms in fluid mechanics

### Total Pressure or Head Loss in Pipe or Duct Systems

Major and minor loss in pipe, tubes and duct systems

### U-Tube Manometer

The inclined and vertical u-tube manometers are inexpensive and common in the differential pressure measurement with flow meters like pitot tubes, orifices and nozzles

### Universal and Individual Gas Constants

The Universal and Individual Gas Constants in fluid mechanics and thermodynamics. Individual gas constant is given for the most common gases.

### Velocity Head

Dynamic pressure and velocity head

### Viscosity Converting Chart

Convert between the viscosity units *Centiposes, milliPascal, CentiStokes and SSU*

### Viscous Liquids - Friction Loss

Friction loss in steel pipes - for fluids with viscosities ranging *32 - 80000 SSU*

### Water - Absolute or Dynamic Viscosity

Absolute or dynamic viscosity of water in centipoises for temperatures between *32 - 200 ^{o}F*

### Water - Boiling Points at Vacuum Pressure

Online calculator, figures and tables giving the boiling temperatures of water in varying vacuum, SI and Imperial units.

### Water - Dynamic and Kinematic Viscosity

Online calculator, figures and tables showing viscosity of water at temperatures ranging from 0 to 360 °C (32 to 675 °F) - Imperial and SI Units

### Water Flow in Tubes - Reynolds Number

Clean cold waterflow in pipes and the Reynolds number

### Water Steam - the Critical Point and the Triple Point

Critical point is where vapor and liquid are indistinguishable and triple point is where ice, water and vapor coexist in thermodynamic equilibrium

### Water Systems - Valves and *K*_{v} diagram

_{v}

*K _{v}* diagram for sizing control valves

### Weber Number

Introduction to the Weber Number

### Wind Energy

Available wind energy

### Wind Power

Power generated from the wind

### Wind Shear

Wind slowed down at surface by trees and obstructions

### Wind Turbine Power Calculator

Online wind turbine calculator