79583 - Fluid Machines T

Learning outcomes

The students will achieve the knowledge on the basic thermodynamics and the fluid dynamics of fluid machinery with particular reference on:

- Fluid machinery layout, working principles, and classification.

- First Law of Thermodynamics for closed and open systems.

- The energy exchange between the fluid and the fixed/moving blade in roraty machinery.

- Volumetric reciprocating compressor basic operating principles

- Volumetric positive vane displacement compressor basic operating principles, with brief focus on vacuum pumps

- Internal combustion engine thermodynamics and combustion principles

 

Course contents

THERMODYNAMICS OF FLUID MACHINERY
Classification of Fluid Machinery. Types of thermodynamic cycles.

The first law of thermodynamics for closed and open systems. The Second law of thermodynamics. 

Work transfer between fluids and fixed/moving blades in roraty machinery

Work transfer in compression expansion processes. Isoentropic and politropic compression and expansion efficiencies.


RECIPROCATING DISPLACEMENT AND ROTARY COMPRESSORS

Reciprocating compressors: construction characteristics; compressor cycle; valves; capacity control. Indicating diagram.

Positive displacement compressors. Working principle; characteristics, advantages, disadvantages and application range of the different types. 

Brief introduction to vacuum applications

 

RECIPROCATING INTERNAL COMBUSTION ENGINES

1. Engine layouts, application overview, efficiency.

2. Engine classification criteria.

3. Spark ignited and compression ignition combustion system features. Limit to the delivered power in SI engines.

4. The indicating in-cylinder theoretical and actual traces.

5. The thermodynamic cycles and emphasis on volumetric compression ratio. The themodynamic efficiency of Sabathè cycle.

6. Analytical derivation of the work per cycle, power and torque with emphasis on air trapped mass as limiting factor. The volumteric efficiency.

7. The indicated and brake mean effective pressure. Downsizing concept

8. Power, torque and brake specific fuel consumption diagrams

9. Load variation strategies for SI and CI engines

 

 

Readings/Bibliography

1. Lecture notes

2. Lectures notes available on AMS-CAMPUS (Readings)

     3. Books:

3.1 Sistemi Energetici e Macchine a Fluido" G: Negri di Montenegro, M. Bianchi A. Peretto-Pitagora Editore.

3.2 " Macchine" G. Cantore, Esculapio Bologna

Teaching methods

Class Teaching ed application to actual test cases

Assessment methods

The assessment methods is intented to check the students outcomes with emphasis on the the full achievemnts of:

1. Thermo-dynamics principles applied to energy transfer or conversion in the fluid machinery presented

2. Knowledge of fluid machinery layouts, working principle and applications areas

3. Accuracy and robustness in the analytical derivation of equations and relations with focus on the clear and clean statement of goals, hypothesis and results achieved

 

The assessment of the learing outcomes will be performed through a written examination including three open questions.

Teaching tools

Teaching class is supported with slide show

Office hours

See the website of Gian Marco Bianchi