Turbomachinery

The subject deals with the operation of turbine machines, ie fans, compressors, pumps, and turbines. The study material is divided into twelve chapters. First, the division of turbine machines is given in the first introductory chapter. Later the efficiency of turbine machines is discussed. Based on the control volume approach, we derive the energy equation for turbine machines. Euler equation and velocity triangles are given for radial and axial pumps and turbines. In this case, stagnation pressure and enthalpy are considered. Based on the Euler equation, the influence of the blade angles on characteristics is explained. Later, the application of the theory of similarity in the case of turbine machines, we consider the pressure, flow and power numbers, and specific speed. Since the development and production of water turbines in Slovenia are important areas of mechanical engineering, we introduce Pelton, Francis, Kaplan, and bulb water turbines including the elements of the flow tracts of water turbines such as dams, penstocks, trash racks, surge tanks, guide vanes, turbine blades, draft tube, lubrication systems, bearings, gates, flow fields, etc., and the process of manufacture of water turbines. Water turbines characteristics, hill diagrams, and operation in four quadrants are presented. We discuss cavitation in pumps and turbines and perform a simple design procedure for blade angles of a water turbine concerning net positive suction head requirements and reactivity.

Study material is available in English.

Prerequisites:

Finished 1st cycle academic study program.

Experimental Modeling in Energy and Process Engineering

The subject deals with the experimental and modeling methods in energy and process engineering. We position the subject topics as a small subsection of the digital twin. In the introduction, students will learn the basics of turbine machinery and dimensional analysis.

In the part related to experimental work, measuring stations design is introduced for measurement of fans, pumps, and turbines characteristics. Major measuring station types are discussed. Measurement equipment and its installation are explained. This includes pressure, volume flow rate, torque, rotational frequency, electric current, voltage, power, etc. The operation of electric motors and generators operation is explained. Students learn how to design an experiment and pre-process the data before the modeling.

A section on modeling methods focuses on linear statistical models as grey or black boxes. Parametric and non-parametric models are compared. Properties of linear models are explained. Methods on how to determine model parameters and evaluate their quality will be discussed. The subject will finish with a few examples.

Study material is available in English.

Prerequisites:

Finished 1st cycle academic study program.