Fluid Mechanics and Thermodynamics Quiz

Fluid Mechanics and Thermodynamics

• A fluid is a substance that deforms continuously when subjected to a tangential or shear stress.
• Fluid mechanics studies fluids in motion (fluid dynamics) or at rest (fluid statics).
• Examples of fluids include liquids, gases, blood, air, water, oil, etc.

Fluid Properties

• Density (ρ): Mass per unit volume (kg/m³). Calculated as the limit of mass divided by volume as the volume approaches zero.
• Specific Weight (γ): Weight per unit volume (N/m³). Calculated as density multiplied by acceleration due to gravity (γ = ρg).
• Specific Volume (ν): Volume occupied by unit mass of fluid (m³/kg). The reciprocal of density (ν = 1/ρ).
• Specific Gravity (s): Ratio of density of a liquid at actual conditions to the density of pure water at 101 kN/m² and 4 °C. The specific gravity of a gas is the ratio of its density to that of either hydrogen or air at some specified temperature or pressure.

Viscosity

• Viscosity is a fluid's resistance to shearing stresses.
• Dynamic viscosity (µ, also called viscosity) is the constant of proportionality in Newton's Law of viscosity which relates shear stress to the rate of shear strain.
• Kinematic viscosity (ν) is the ratio of dynamic viscosity to density (ν = µ/ρ).

Temperature and Pressure Effects on Viscosity

• Liquid viscosity decreases with increasing temperature.
• Gas viscosity increases with increasing temperature.
• Viscosity of most liquids is not significantly affected by pressure changes at ordinary conditions.
• Pressure slightly affects viscosity in some oils.

Surface Tension

• Cohesion is the intermolecular attraction between molecules of the same liquid.
• Adhesion is the attraction between the molecules of a liquid and another substance.
• Surface tension is due to cohesion at the liquid's free surface.

Capillarity

• Capillarity is the ability of a liquid to flow in narrow spaces without the assistance of, or even in opposition to, external forces like gravity.
• Capillary action is due to the forces of cohesion and adhesion.
• Capillary rise (or depression) depends on the tube diameter as well as the surface tension and contact angle.

Compressibility

• Compressibility is the ability of a fluid to change volume in response to changes in pressure.
• Bulk modulus of elasticity (K) is a measure of a fluid's resistance to compression.
• The higher the K-value for a fluid, the less compressible it is, and the lower (or smaller) the reciprocal (1/K), the more compressible it is.

Test your knowledge on fluid mechanics and thermodynamics, covering essential properties, classifications, and principles of fluids. This quiz will challenge your understanding of concepts like density, viscosity, and specific gravity. Perfect for students studying these fundamental topics in science and engineering.