# APPLIED PHYSICS A

## Learning outcomes of the course unit

To introduce the students to the basic concepts of thermodynamics and fluid flow applied to the analysis of the transformation of energy (thermal and mechanical) and of the transfer of thermal energy.

## Prerequisites

Basic knowledge of General Physics and Applied Mathematics.

## Course contents summary

Thermodynamics. Definitions: systems and properties. Units (SI). Closed and open systems. Forms of energy. First Law. Second law. Entropy. Irreversibility. Closed systems: conservation of mass, conservation of energy. Open systems: definitions, conservation of mass, conservation of energy, steady and transient processes. Properties of pure substances, equilibrium diagrams (p,v) (p,T). Incompressible substances and their properties. Vapours: quality and other properties. Ideal gas. Real gas. Van der Waals equation. Law of corresponding states. Compressibility factor. Vapor power cycles: Rankine cycle, ideal cycle, reheat. Refrigeration vapour cycle. Coefficient of performance. Thermodynamic efficiency. Simple multicomponents systems. Ideal gases mixtures. Mixtures of air and water vapour. Specific umidity. Psicrometric diagram?

Fluid flow: Physical aspect of the fluid flow. Coefficient of viscosity. Laminar and turbulent flow. Boundary layer. Newton law. Continuity equation. Navier vectorial equation. Reynolds number. Fluid flow in pipes. Integral equations. Energy bilance equation. Bernoulli equation. Friction losses. Velocity and mass flow rate measurements in fluids. Compressible fluids. Mach number. Sound equation. Isoentropic flow of compressible fluids in ducts of variable section. De Laval nozzle.

Heat transfer: Conduction. Fourier law. Energy balance equation. Fourier equation. Steady state conduction. Electrical analogy. Convection. Dimensional analysis. Thermal boundary layer. Forced, natural and mixed convection. Thermal radiation. Definitions. Laws of thermal radiation: Plack's law, Stefan-Boltzmann law. View factor. Applicaions to thermal radiation heat transfer between black and grey surfaces. Overall heat transfer coefficient. Finned surfaces. Heat exchangers. Logaritmic mean temperature difference. Efficiency of the heat exchanger.

## Recommended readings

A. COCCHI: "Elementi di termofisica generale e applicata", Società Ed. Esculapio, Bologna, 1990.

J. H. Lienhard IV and J. H. Lienhard V: ¿A Heat Transfer Textbook¿, download at the address: http://web.mit.edu/lienhard/www/download-ahtt.shtml

## Teaching methods

Written and oral examination.

In order to make the students develop an analytical and problem-solving skill, part of the course is focused on exercises where the conceptual principles find practical application.