Fluid statics, kinematics and dynamics. Pressure and gravity waves. Non-ideal fluids, viscosity and turbulent motion.
Temperature measurements. Ideal and real gas. Calorimetry and transmission of heat. Thermodynamics: first and second principle. Entropy, enthalpy and thermodynamic potentials. Statistical physics: Kinetic theory, H-theorem, Maxwell-Boltzmann distribution, classical statistical ensembles.
"Elementi di Meccanica dei Fluidi, Termodinamica e Fisica Statistica", E. Landi Degl'Innocenti, Springer
Learning Objectives
Fundamental knowledge in fluidodynamics, thermodynamics and statistical mechanics. Basic competences of the physiscist relatively to classical physiscs. Skills in solving numerical problems of physics, in identifying the essential elements of a physical process, in working out physical models and verifying their validity, in guessing structural analogies among different phenomenological scenarios.
Prerequisites
Required courses: Matemathical Analysis I
Teaching Methods
56 hours of lecturing,
24 hours of exercises.
Further information
Office hours: online on Webex until December 31, 2020 (access via Moodle-Webex connection); afterwards, according to University rules (still to be decided).
Type of Assessment
Oral examination.
Course program
PROLOGUE
A mechanical model of matter. Condensed phases of matter. Microscopic and macroscopic description. Numerical simulations.
FLUID MECHANICS
Difference beetween solid and fluid substances. Fluid Statics. Surface and volume forces. Concept of pressure. Pascal principle. The fundamental law of hydrostatic. Differences between liquids and gases. Compressibility coefficient. Variation of the pressure with height. Torricelli experiment. Unit of measurement for pressure. Archimede's principle. Center of buoyancy. Flotation and flotation stability. Surface and capillarity phenomena. Surface tension. Cohesion and adhesion forces. Tate and Jurin laws. Fluid kinematics. Lagrangian and Eulerian descriptions. Eulerian derivative. Advection term. Continuity equation. Leonardo's principle. Flux lines and flux tubes. Massic and volumetric flow rate. The fundamental law of hydrodynamics for ideal fluids. Bernoulli theorem for a liquid and for a compressibile fluid. Piezometric height and height of stop. Torricelli theorem. Applications of the Bernoulli theorem: Venturi tube and Pitot tube. Pressure waves. Concept of deformation. Sound velocity. Frequency and angular frequency, wavenumber, wavelenght, phase. Outline on gravity waves (surface waves). Dispersion relation for gravity waves. Dynamics of non-ideal fluids. Dynamic viscosity and kinematic viscosity. Newton formula. The fundamental law of non-ideal fluid hydrodynamics. Poiseuille law. Turbulent motion. Reynolds number. Drag force. Aerodynamic lift. Magnus effect.
THERMODYNAMICS
The zero principle of thermodynamics. Thermodynamic and thermal equilibrium. Thermal expansion of physical bodies. Freezing and melting points. Thermometric properties and substances. Scales of temperature. Concept of thermal equilibrium. Gases laws (Boyle-Mariotte, Gay-Lussac, and Avogadro laws). The state equation of ideal gases. The ideal gas thermometer. Behaviour of real gases. Concepts of critical temperature, critical pressure and critical volume. Van der Waals equation. Phase transitions in a pure substance. Heat quantity. Calorimeters. Specific heat and latent heat. The Joule heat apparatus. Mechanical equivalent of the calorie. Equivalence between heat and work. The transmission of heat. Conduction. Concept of thermal conductivity. Fourier postulate. The equation of heat diffusion. Convection. Black-body radiation. Planck law and Stefan law. Quasi-static thermodynamic transformations. Work done by a hydrostatic system. The first principle of thermodynamics. Concept of internal energy. Illustrations of the first principle and application to simple cases. Specific heats of gases. Constant-volume and constant-pressure specific heats and their relationship. Adiabatic transformations of an ideal gas. The second principle of thermodynamics. Heat engines and their efficiency. The Carnot theorem. Carnot cycle. Thermodynamic definition of temperature. The Clausius inequality. Definition of entropy. Illustrations of the concept of entropy. Consequences of the first and of the second principle: the internal energy equation and the TdS equation. Clayperon equation. The statistical meaning of entropy. Concept of thermodynamical probability. The Boltzmann equation. Enthalpy and thermodynamic potentials. Thermodynamic cycles (Rankine, Otto, and Diesel cycles). Refrigerating engines and heat pumps.
STATISTICAL PHYSICS
Elementary probability concepts. Introduction to the kinetic theory of the gases. The Clausius model. Mean quadratic velocity. Virial theorem. Maxwellian distribution of velocities. Mean free path. Poisson distribution. Distribution of the distances among particles. Transport phenomena. Random-walk. Brownian motion. Disorder and its measurement. H-theorem. General laws of Statistical Thermodynamics. Gibbs ditribution. Fluctuations. Systems of identical particles: Boltzmann equation. Equipartition of energy. Entropy of the perfect gas. Statistics of open thermodynamical systems.