Applied Mechanics for Machinery and Machinery

Teaching is divided into two parts. In the first part, the basic concepts of mechanics applied to machinery are provided; the second part describes the hydraulic machines

Frontal lessons with projector and blackboard.

Lectures: 21 hours

Exercises: 39 hours

Exam:

Written exercises
Oral examination

Should teaching be carried out in mixed mode or remotely, it may be necessary to introduce changes with respect to previous statements, in line with the programme planned and outlined in the syllabus.

Knowledge of:

• Physics 1 (forces and torques, Newton's principles, statics, friction, dynamics and equations of motion, free body diagrams)
• Calculus 1 and 2 (series of functions, partial derivatives, ordinary differential equations)
• Linear algebra (operations on vectors and matrices)
• Hydraulics and Bernoulli's theorem

1. GENERALITY ON MECHANISMS Machines and mechanisms, kinematic pairs, degrees of freedom of the kinematic pairs, degrees of freedom of planar and spatial mechanisms.  2. EFFICIENCY. Definition of mechanism efficiency, in series and parallel efficiency, inverse motion.  3. FRICTION AND WEAR. Coefficient of friction and work, notes on the theory of sliding friction, rolling friction, friction circle. Examples: revolute pair, inclined plane. Contact pressures distribution and Reye's hypothesis. Applications: flat sliding pair, revolute pair. 4. GEAR WHEELS. Friction gears, conjugate profiles, primitive and fundamental circles, the definition of a circle's involute. Spur gears and relative dimensioning, determination of the arc of action, non-interference condition. 5. Gearboxes. Ordinary gearboxes, planetary gears and Willis’ formula, automotive differential. Examples and exercises on gearboxes.  6. FLEXIBLES. Lifting devices, elastic and inelastic stiffness, pivot friction, lifting hoists.

HYDRAULIC MACHINES

1. RECALLS ON FLUIDS AND THEIR PROPERTIES. Dynamic and kinematic viscosity, Reynolds number, Mass conservation, Bernoulli equation, distributed and concentrated pressure losses. 2. TURBOMACHINES. General characteristics, velocity triangles, fundamental turbomachine or Euler equation and internal work, organic, hydraulic and volumetric efficiency, fluid dynamics similarity and dimensionless coefficients, Balje diagram. 3. TURBOPUMPS. Characteristic curves, centrifugal pumps, mixed-flow and axial pumps, dimensioning of a turbo pump. Examples. 4. VOLUMETRIC PUMPS. Classification, Piston pumps, displacement, capacity and volumetric efficiency, power and efficiency. 5. MATCHING OF PUMP AND SYSTEM. Operation point of a plant, cavitation, NPSH and Thoma parameter, pump choice and rotation speed. 6. ACTION HYDRAULIC TURBINES. Pelton turbine, speed triangles, internal work, efficiency and losses, specific speed and diameter and design. 7. REACTION HYDRAULIC TURBINES. Francis turbine, axial flow and Kaplan turbine, reaction rate, speed triangles, internal work, efficiency and loss, sizing, regulation, diffuser. Examples.

1. Massimo Callegari, Pietro Fanghella, Francesco Pellicano, “Meccanica applicata alle macchine”, UTET Università

2. G. Cornetti, "Macchine Idrauliche", Edizioni il Capitello Torino.

Insights:

3. Funaioli E., Maggiore A., Meneghetti U., “Lezioni di Meccanica Applicata alle Macchine – Vol. 1”, Pàtron Editore.
4. Jacazio G., Piombo B., “Meccanica Applicata alle Macchine – Vol.2”, Levrotto & Bella Torino.

course lecture notes

The exam includes:

- two ongoing tests, divided for each part of the program, to be carried out during the lessons.

For those who have not completed or have not passed the ongoing tests:

- written test (3 hours)

- possible oral exam with questions and exercises on the two parts of the course at the request of the student

- Flexibles

- Friction

- efficiency of a system

- dynamics of the roller

- motor-load matching

- design of a turbomachine

- ideal and real cycle of a volumetric pump

- efficiency of a turbopump

- efficiency of a turbine