Kinematics, Dynamics, Static. Friction forces. Work and energy. Thermology and thermodynamics.
Machines classification and efficiency. Power transmissions. Hydraulic, pneumatic, thermal and electric machines and their agricultural use. Tractors and farm equipments: technical and operational aspects; coupling. Selecting and dimensioning farm machinery. Cases of study.
Bodria L., Pellizzi G., Piccarolo P., Meccanica Agraria, vol. I e II, Edagricole, ISBN-88-506-5131-7
Learning Objectives
Knowledge acquired: basic knowledge of Physic and Mechanics suited to understand the functioning of agricultural machinery and the energy use. Knowledge of farm machinery and their performances
Competence acquired (at the end of the course):
Understanding main farm plants and machinery operation and how to evaluate and improve their performance.
Skills acquired (at the end of the course):
sizing and selecting tractors and equipments for the main farm and field works.
Prerequisites
Courses recommmended: Mathematics
Teaching Methods
CFU: 9
Total hours of the course: 225
Hours reserved to private study and other indivual formative activities: 150
Contact hours for:Lectures: 48
Contact hours for: Laboratory/practice: 20
Seminars/excursions: 4
Intermediate examinations: 1
Further information
Frequency of lectures, practice and lab, although non compulsory, is strongly recommended
Teaching tools
Video projector, PC, overhead projector, experimental fields, labs
Type of Assessment
Exam modality: written test and oral examination on farm machinery recognition
Course program
Path and motion equation. Mean and instantaneous velocity. Acceleration. Rectilinear uniform motion and motion composition. Circular and periodic motion. Fundamental laws in the translation dynamics. Constrained motion. Rotary motion. Moment of force. Equations of dynamics and statics of planar forces. Pressure and hydrostatics. Differential manometer, hydraulic press. Friction forces: sliding, rolling. Traction forces. Viscosity. Apparent forces. Work and power: of a force, a torque and of pressure. Translation and rotary Power. Kinetic energy theorem. Conservative forces and potential energy. Thermodynamic; temperature and Calorimetry. First law, state transformations, direct and reverse cycle. Second law, entropy. Carnot cycle and theorem.
Machines classification. Efficiency. Power transmission. Hydraulic machines. Fans and wind machines. Endothermic motors. Fundamental cycles, main components and working principle, efficiency, power and consumption. Characteristic curves and performance. Refrigerators. Voltage and electric current. Power, Joule effect. Alternate current. Three-phase systems. Electric generators and motors (general). Transformers, accumulators. Agricultural tractors. Types, structure and main parts. Tyre and tracks. Driving system. Tractor-tools matching. Hydraulic lift. Power take-off. Driving wheel, adhesion, rolling resistance. Available tractor-pull. Tractor use and related efficiency. Tractor selecting and sizing. Power requirements and maximum power. The case of plowing. Tractor-pull verification. Equipments working by the PTO and combined. Power use and fuel consumption. Tilling implements. Equipments for fertilization, seeding and crop protection. Equipments and combines for harvesting. Selection and sizing of farm machinery. Work capacity, available time and working module of field machinery.