Fundamentals of Fluid Mechanics

The thickness of the boundary film is primarily influenced by the velocity, viscosity, density, and temperature of the fluid.

Laminar flow is characterized by fluid layers moving smoothly over one another with no mixing, and the velocity is highest at the center of the pipe and zero at the pipe wall.

Turbulent flow typically occurs at Reynolds numbers greater than or equal to 4000.

<p>The Reynolds number helps characterize flow regimes, indicating whether the flow is laminar, transitional, or turbulent based on its value.</p> Signup and view all the answers

<p>Transitional flow may exhibit characteristics of both laminar and turbulent flow.</p> Signup and view all the answers

<p>Turbulent flow reduces the formation of deposits on heat exchangers by keeping particles in suspension more effectively.</p> Signup and view all the answers

<p>The boundary film acts as a thermal resistance layer that impacts the rate of heat transfer between the fluid and the surface.</p> Signup and view all the answers

<p>In streamline flow, particles can experience a larger range of residence times, which is crucial for processes like heat treatment of liquids.</p> Signup and view all the answers

<p>An ideal fluid is defined as incompressible, has zero viscosity, and is irrotational. It is considered imaginary because no real fluid possesses these perfect characteristics under natural conditions.</p> Signup and view all the answers

<p>Real fluids possess viscosity, enabling them to sustain frictional and shear stresses, unlike ideal fluids which have zero viscosity.</p> Signup and view all the answers

<p>Newtonian fluids are those that exhibit a linear relationship between shear stress and shear rate. An example of a Newtonian fluid is water.</p> Signup and view all the answers

<p>Shear stress is the force applied parallel to the fluid’s surface that initiates flow. It determines how the fluid layers move relative to each other.</p> Signup and view all the answers

<p>As temperature increases, the viscosity of most liquids decreases, making them flow more easily.</p> Signup and view all the answers

<p>Pseudoplastic fluids decrease in viscosity with increasing shear rate, while dilatant fluids increase in viscosity with increasing shear rate.</p> Signup and view all the answers

<p>Shear rate describes the rate at which adjacent layers of fluid move relative to one another, influencing the fluid's viscosity and flow behavior.</p> Signup and view all the answers

<p>As the concentration of a non-Newtonian fluid increases, its viscosity may also increase, leading to a transition from Newtonian to non-Newtonian behavior.</p> Signup and view all the answers

<p>The flow of brake oil is determined to be turbulent because the Reynolds number (Re) calculated is 73,571, which is greater than 4,000.</p> Signup and view all the answers

<p>The Reynolds number (Re) for engine oil is 1,144.</p> Signup and view all the answers

<p>The Reynolds number is influenced by fluid density, flow velocity, characteristic length (diameter), and viscosity.</p> Signup and view all the answers

<p>Liquids can often be treated as incompressible because their volume changes minimally under normal pressure variations.</p> Signup and view all the answers

<p>The bulk modulus of elasticity represents the measure of a fluid's resistance to compression and is defined by the relationship K = -dP/(dV/V).</p> Signup and view all the answers

<p>The negative sign in the compressibility formula accounts for the decrease in volume (dV) when pressure (dP) increases.</p> Signup and view all the answers

<p>Higher flow velocities generally increase the Reynolds number, which can shift the flow from streamline to turbulent.</p> Signup and view all the answers

<p>Under normal conditions, the compressibility of liquids is often negligible due to their close particle packing, but it becomes significant under high pressures.</p> Signup and view all the answers

<p>The formula is $P = \rho hg$.</p> Signup and view all the answers

<p>Terminal velocity is the constant velocity attained when the net gravitational force equals the upward drag force.</p> Signup and view all the answers

<p>A particle will rise if its density is smaller than that of the fluid.</p> Signup and view all the answers

<p>Hydrodynamics focuses on fluid flows with no density changes and the forces on bodies immersed in fluids.</p> Signup and view all the answers

<p>The drag coefficient (C) quantifies the drag force experienced by an object moving through a fluid.</p> Signup and view all the answers

<p>Gas dynamics studies fluid flows where density changes occur, particularly high-speed gas flows.</p> Signup and view all the answers

<p>Ideal fluids have no viscosity and do not resist flow, while real fluids have viscosity and can exhibit resistance.</p> Signup and view all the answers

<p>The fluid returns to its original state of rest after disturbance by the body passes.</p> Signup and view all the answers

<p>The relationship is given by the equation $\rho = \frac{M}{V}$.</p> Signup and view all the answers

<p>Specific weight can be defined as $\omega = \rho g$, where $g$ is the acceleration due to gravity.</p> Signup and view all the answers

<p>Specific gravity is the ratio of the density of a liquid to the density of water, calculated as $\text{S.g} = \frac{\rho_{\text{liquid}}}{\rho_{\text{water}}}$.</p> Signup and view all the answers

<p>The equation of state is $pv = mRT$, where R represents the gas constant.</p> Signup and view all the answers

<p>Density can be expressed using the equation $p = \frac{m}{v} = \rho RT$ derived from the state equation for gases.</p> Signup and view all the answers

<p>As the compression pressure increases, the resistance to compression (K) also increases.</p> Signup and view all the answers

<p>Specific volume is the reciprocal of specific weight, representing the volume occupied by a unit weight of the fluid.</p> Signup and view all the answers

<p>The gas constant (R) is unique for each type of gas, affecting its behavior under varying conditions.</p> Signup and view all the answers

<p>Cv represents the specific heat capacity at constant volume.</p> Signup and view all the answers

<p>Cp is the sum of the increase in internal energy and the work of expansion, expressed as h = u + pv.</p> Signup and view all the answers

<p>The relationship is given by Cp = Cv + R, where R is the universal gas constant.</p> Signup and view all the answers

<p>The specific heat ratio, denoted as γ, is defined as γ = Cp/Cv.</p> Signup and view all the answers

<p>Cv = 1298.75 J/kg.K.</p> Signup and view all the answers

<p>Cp is derived as Cp = Cv + R, substituting the value of Cv into this equation.</p> Signup and view all the answers

<p>The equation is $rac{\delta h}{\delta T} = \frac{\delta u}{\delta T} + R$.</p> Signup and view all the answers

<p>The universal gas constant R signifies the relationship between temperature, volume, and pressure in an ideal gas.</p> Signup and view all the answers

A thin layer of fluid that forms along a surface, influenced by factors like velocity, viscosity, density and temperature.

A fluid flow characterized by smooth, parallel layers that move without mixing, often associated with low flow rates and high viscosity.

A fluid flow characterized by chaotic, random mixing of fluid layers, often associated with higher flow rates and lower viscosity.

The velocity of a fluid in a pipe is highest at the center and zero at the pipe wall.

A dimensionless number used to characterize the flow regime of a fluid, indicating whether it's laminar, transitional, or turbulent.

A flow regime where the fluid flow is between laminar and turbulent, exhibiting characteristics of both.

Thinner boundary layers promote higher rates of heat transfer.

Higher flow rates create more turbulent flow and thinner boundary layers.

A fluid that is incompressible and has no internal resistance to flow (zero viscosity). In addition, ideal fluids do not rotate about their center of mass (irrotational).

These fluids have viscous properties, experience frictional and shear stresses, and dissipate mechanical energy into heat.

The resistance of a fluid to flow. It arises from the internal friction between fluid layers as they move past each other.

Fluids that exhibit a linear relationship between shear stress and shear rate. The viscosity remains constant regardless of the applied shear stress.

Fluids that exhibit a non-linear relationship between shear stress and shear rate. Their viscosity changes with the applied shear stress.

Non-Newtonian fluids whose viscosity decreases with increasing shear stress.

Non-Newtonian fluids whose viscosity increases with increasing shear stress.

The behavior of a fluid when force or shear stress is applied.

The measure of mass per unit volume.

The measure of weight per unit volume.

The relationship between density and specific weight.

The ratio of a fluid's density to the density of water at 4°C.

An ideal gas that obeys the equation of state: pv = mRT.

A constant specific to each gas in the equation of state.

The internal energy change of a system due to heat addition at constant volume.

The equation describing the relationship between pressure, volume, mass, gas constant, and temperature for a perfect gas.

Pressure is the force exerted per unit area. In this context, the pressure due to the weight of a fluid column is calculated by dividing the weight of the fluid column by its base area. The weight of the fluid column is determined by its volume (height x base area) multiplied by the density and acceleration due to gravity.

Terminal velocity is the constant speed attained by a freely falling object when the force of gravity is balanced by the opposing force of air resistance. The object stops accelerating and falls at a steady rate.

The terminal velocity of a particle in a fluid depends on various factors, including its mass, density, projected area, and the fluid density. This formula allows us to calculate the terminal velocity for particles in fluids.

Hydrodynamics focuses on the flow of liquids and gases at low speeds where there are no significant density changes. It explains how fluids interact with objects and how fluid motion is influenced by forces.

Gas dynamics deals with the flow of gases at high speeds where density changes are significant. It explores how gases behave under extreme conditions, leading to studies in fields like diffusion, thermodynamics, and aerodynamics.

Describes fluid flow where fluid particles move in smooth, parallel layers without mixing.

The resistance to flow caused by friction between fluid layers, higher in turbulent flow.

The ability of a fluid to resist deformation under applied stress. Higher viscosity means thicker and slower flow.

The property of a fluid to resist compression, indicating how much its volume changes under pressure.

A measure of a fluid's resistance to compression, defined as the change in pressure over the fractional change in volume.

For practical purposes, liquids can be considered incompressible. However, when subjected to extremely high pressure, their compressibility becomes significant.

The amount of heat required to raise the temperature of a system by one degree Celsius at constant volume. It represents the change in internal energy per unit temperature change.

The amount of heat required to raise the temperature of a system by one degree Celsius at constant pressure. It represents the change in enthalpy per unit temperature change.

The sum of the internal energy and the product of pressure and volume. It represents the total energy content of a system at constant pressure.

The ratio of the specific heat at constant pressure (Cp) to the specific heat at constant volume (Cv). It represents the efficiency of a system in converting heat energy into work.

The relationship between Cp, Cv, and the gas constant (R) for an ideal gas. It shows that Cp is always greater than Cv by the value of R.

A measure of the energy stored within a system, representing the kinetic energy of its molecules. It is a function of temperature.