With recent developments in the information-technology field, cloud-based application deployment has become one of the most popular methods of software distribution. Likewise, image-based methods are in some fields of experimental mechanics already regarded as valid alternatives to conventional measurement methods. The Python programming ecosystem offers various frameworks for both web application development and image-based displacement identification. The goal of this thesis is to assess the available tools and implement an image-based displacement identification system utilizing a web application user interface, with the possibility of extending the program into an independent cloud application.

Contact person: Prof. Dr. Janko Slavič

Webpage of the laboratory: http://www.ladisk.si/

The aim of the study is to compare the limit of linear viscoelastic behavior of polymeric material if it is determined by a static test or by a dynamic test. The task includes: a review of the relevant literature, the preparation of samples for static and dynamic testing, the measurement of LTVE at different temperatures on the modular rheometer, and an analysis of the results for determining the two limits of linear behavior.

Contact person: Assist. Prof. Dr. Lidija Slemenik Perše

Webpage of the laboratory: http://web.fs.uni-lj.si/cem/

In the diploma thesis, a model and analysis of the current energy needs for cooling and heating for a real project (hotel) must be established using the TRNSYS simulation tool. Currently, the hot water is prepared with an oil boiler, and the cold is produced with water chiller (connection with the sea). In the second phase, the model needs to be upgraded and a heat pump should be included in it, which would simultaneously take advantage of heating and cooling. By parametric analysis, it is necessary to determine the best configuration of the system so that the energy savings achieved are the greatest.

Contact person: Assoc. Prof. Dr. Uroš Stritih

Webpage of the laboratory: http://lab.fs.uni-lj.si/los1/

The use of several solid-lubricant nanomaterials as additives in lubricants present a promising new lubrication technology that combines the benefits of liquid lubrication with the physically based effect of nanoparticles. This would lead to a decrease in the toxic emissions and would eliminate the need for a tribochemical activation. In order to make such lubricants suitable for lubrication of various surfaces, e.g. DLC coatings, their tribological properties, such a friction and wear, need to be studied in detail.

Within this topic the emphasis will be on the wear analysis of contacting surfaces after tribological test performed under different conditions and upon tribofilm removal. The wear analysis will be performed using optical interferometer and scanning electron microscope.

Contact person: Prof. Dr. Mitjan Kalin

Webpage of the laboratory: https://www.tint.fs.uni-lj.si/

Expanded polystyrene is one of most commonly used materials for packaging of sensitive products that must arrive undamaged from the production line to the costumer. Although its wide use the expanded polystyrene is a complex material showing nonlinear characteristics in relation to strain and strain rate. The purpose of thesis is to study the characteristics of expanded polystyrene of given density and implement them into numerical model. Further the modelling of expanded polystyrene structure’s response under static and impact loading is expected with nonlinear static and explicit transient analysis, respectively. The actual experiments of static and impact loading of expanded polystyrene should also be performed and compared to the numerical results.

Contact person: Prof. Dr. Janko Slavič

Webpage of the laboratory: http://www.ladisk.si/

By gas dispersing into liquids, the basic characteristics such as for example, the mixing power and mixing time and the rate of mixing are of crucial importance for the optimum execution of the technological process.

The work is an experimental – analytical nature in which include:

• Measurements of the basic characteristics of a newly developed mixer in
• standard and non – standard geometrical ratio of mixing vessel/stirrer for
• different hydrodynamic regimes.

The measurements will take place at the pilot experimental facility at the Laboratory for Fluid Dynamics and Thermodynamics.

Contact person: Assist. Prof. Dr. Andrej Bombač

Webpage of the laboratory: http://lab.fs.uni-lj.si/lfdt

The subject deals with one of the most geometrically simple solutions for the continuous mixing of gas and liquid phase. Gas is injected through the channel wall into the liquid cross flow. Different combinations of phase flows lead to the formation of different two-phase flow regimes, affecting the heat, mass and momentum transfer. Consequently, the knowledge of mechanisms for the transition between flow regimes is of key importance.

In the framework of this thesis, the development of a laser system is expected. The test section should be simultaneously through-lightened with several lasers to collect the data on flow regimes. By means of visualization, a flow pattern will be assigned to the particular shape of the laser system signal. In this way, a long time period observation will be possible, giving statistically relevant flow indicators. Special emphasis will be on the development of flow pattern maps and on the study of regime stability. The indicators of the flow regime transition would be used to evaluate the optimal heat and mass transfer in the device.

Contact person: Assist. Prof. Dr. Matjaž Perpar

Webpage of the laboratory: https://www.fs.uni-lj.si/en/faculty_of_mechanical_engineering/about_faculty/departments_and_laboratories/laboratories/2005012810071882/

The aim of the study is to determine the limit of linear viscoelastic behavior (LTVE) of partially crystalline polymer at different temperatures. The task includes: a review of the relevant literature, the preparation of cylindrical samples, the measurements of LTVE at different temperatures on the modular rheometer, and the analysis of the results for determining the limit of linear viscoelastic behavior.

Contact person: Assist. Prof. Dr. Lidija Slemenik Perše

Webpage of the laboratory: http://web.fs.uni-lj.si/cem/

One of the main targets of the Kyoto protocol is reduction of energy consumption. A lot of effort is focused on reducing the energy consumption in buildings, and household appliances are major users of energy. The goal of this thesis is to design a new heat exchanger and to predict heat exchanger geometry according to the dishwasher washing cycle in order to reduce the energy consumption. Heat exchanger configuration design will be made based on numerical results and number of experiments will need to be done as a validation of a numerical model.

Prerequisite knowledge: basic programming knowledge

Contact person: Sr. Dev. Nada Petelin

Webpage of the laboratory: https://lahde.fs.uni-lj.si/en/home/

The ability to predict two-phase flow patterns and transitions between them is one of the key research directions in the world scale. The approach to date was predominantly based on empirical flow pattern maps derived from the experimental research. Consequently, such maps are limited by the application and require the extrapolation of experimental results, which in most cases is not reliable. The solution is to develop new tools based on the flow pattern prediction utilizing the first principles of fluid dynamics and the description of two-phase flow, taking into account the nature of several scales. The long-term goal is to deepen the knowledge about the flow pattern development and to identify the key emergent parameters that would be helpful to build a general tool for the flow pattern estimation.

The task of the thesis is to establish a database system that would allow the systematic collection of experimental and numerical data from various research groups that are working within the ViR2AL Institute. The system should be scalable and adaptive, so it could combine data for different configurations of flow systems at a wide array of process parameters. Finally, the system should allow the storage of key two-phase flow parameters at the appropriated scales.

http://2phaseflow.org

Contact person: Assist. Prof. PhD. Matjaž Perpar

Webpage of the laboratory: https://www.fs.uni-lj.si/en/faculty_of_mechanical_engineering/about_faculty/departments_and_laboratories/laboratories/2005012810071882/

The goal is to develop a user interface, which enables the digital-signal processing of data, on an existing rotor-balancing device. The PLC controller (Beckhoff) will be used to acquire the measured data, which will run simultaneously with the user interface. The user interface will be developed in the Python programming language and will enable the analysis of the measured data and the display of results.

Contact person: Prof. Dr. Janko Slavič

Webpage of the laboratory: http://www.ladisk.si/

Elasto-hydrodynamic lubrication is present in non-conformal contacts, such as rolling bearings, gear, cam followers, etc. These contact commonly operates in full-film lubrication regime, where viscous friction within the lubricating film defines overall friction performance of these contacts. Regarding the contact conditions (load, speed, strain rate) it is of the great importance the proper selection of lubricant. Especially relevant in this term are its rheological properties. In this work student will perform tribological tests on MTM tribometer device with different lubricants and at different conditions to obtain coefficient of friction values. In the second part he will study different theoretical models for modelling EHD friction (Eyring, Carreau-Yasuda) and try to establish (existing and modified) models for measured friction results

Contact person: Prof. Dr. Mitjan Kalin

Webpage of the laboratory: https://www.tint.fs.uni-lj.si/

Heat pumps, or more precisely, cooling cycles have been subjected to numerous optimizations and improvements. One of means to enhance the cooling cycle of a heat pump is to lower the temperature difference between the refrigerant temperature and the heat source. This is possible by enhanced evaporators which use different techniques in order to achieve this goal.

Tasks: Besides literature survey, an extensive set of experimental work should be done by using several different types of heat pump’s evaporators. Furthermore, the student would determine the influence of different enhanced evaporators on the operation of the entire cooling cycle with respect to the normal -unmodified evaporator.

Contact person: Assist. Prof. Dr. Primož Poredoš

Webpage of the laboratory: https://lahde.fs.uni-lj.si/en/home/

Condensation of water vapor in the presence of air is completely altered in terms of wall heat flux and condensate mass flux. The fact is that the air molecules near the liquid – vapor interface act as an additional resistance towards condensation of water molecules in the air – water vapor mixture. The research in this domain has been accelerated in the 80’s and 90’s due to several dangerous events in the nuclear reactors cooling systems.

Tasks: Besides literature survey an extensive set of experimental work should be done. Those measurements would provide a means for validation numerical models. The student would determine the influence of air mass fraction, temperature of moist air as well as temperature difference (moist air, cold surface) on the intensity of condensation heat fluxes and rates of condensed water.

Contact person: Assist. Prof. Dr. Primož Poredoš

Webpage of the laboratory: https://lahde.fs.uni-lj.si/en/home/

Within the assignment, the yield stress of composite materials with a high proportion of solid particles will be determined at different temperatures and different concentrations of solid particles. The second part of the task is designed to model yield stress using existing models.

Contact person: Assist. Prof. Dr. Lidija Slemenik Perše

Webpage of the laboratory: http://web.fs.uni-lj.si/cem/

The aim of the study is to determine the dynamic material properties of various polymer materials in a wide frequency range by performing tests at different temperatures. Within the assignment, it is necessary to: prepare samples for testing, perform DMA tests on a rotary rheometer at different temperatures, compose a master curve under the reference conditions using a frequency-temperature superposition, and compare the results between different polymer materials.

Contact person: Assist. Prof. Dr. Lidija Slemenik Perše

Webpage of the laboratory: http://web.fs.uni-lj.si/cem/

Experimental modal analysis is the procedure for identification of modal parameters (natural frequency, damping coefficient) based on measurement of the vibration response of the structure. Response measurement with high-speed camera is among the new approaches that produces spatially dense information, however some problems must be overcome. The goal of the thesis is to explore different options for displacement identification based on high-speed camera video and research appropriate modal identification approaches. During the thesis, an experiment with high-speed camera will be conducted. The identification of displacements and modal parameters will be implemented in Python programming environment.

Contact person: Prof. Dr. Janko Slavič

Webpage of the laboratory: http://www.ladisk.si/

Thermochromism is subclass of chromogenic phenomena, where visible optical properties change dependence on temperature. This phenomenon could appear in thermoplastics, duroplastics, gels, inks or paints. Colour change of thermochromic materials could be reversible or irreversible. Thermochromic systems are widely used as a carrier in various applications such as smart packaging, security printing, toys and marketing. Thermochromic pigments and their incorporation into mass market polymers have become increasingly important in the art and textile application. With use of 3D printer, a variety of different products could be made. We will focus on use of PLA filaments with incorporated thermochromic pigment. The rheological, thermal, and mechanical properties of both commercial and extruded thermochromic polymer will be investigated.

Contact person: Assist. Prof. Dr. Lidija Slemenik Perše

Webpage of the laboratory: http://web.fs.uni-lj.si/cem/

In many applications, products made of polymeric materials are subject to dynamic (cyclic) loads (typical example: polymer gears). In such cases, material failure often occurs as deformation in the product accumulates over time. The aim of this study is to compare the experimentally measured and predicted material failure due to the accumulation of deformations of dynamically loaded polymeric materials. For this purpose, the candidate will use the existing model for predicting the accumulation of deformations and compare it with the experimentally measured deformation of the material.

Contact person: Assist. Prof. Dr. Lidija Slemenik Perše

Webpage of the laboratory: http://web.fs.uni-lj.si/cem/

The use of several solid-lubricant nanomaterials as additives in lubricants present a promising new lubrication technology that combines the benefits of liquid lubrication with the physically based effect of nanoparticles. This technology would lead to a decrease in the toxic emissions and would eliminate the need for a tribochemical activation. In order to understand lubrication properties as well as effect of various nanoparticles on macro-tribological performance (friction and wear) of the investigated contacts, tribological properties on nano-scale, such as adhesion, friction force, mechanical properties, need to be understand in detail as well.

Within this work the main emphasis will be on the measurements of adhesion and friction force between a graphene platelet and various surfaces, such as various steel, DLC-coatings, ceramics, etc., on sub-nano scale. The measurements will be performed by atomic force microscope.

Contact person: Prof. Dr. Mitjan Kalin

Webpage of the laboratory: https://www.tint.fs.uni-lj.si/

The aim of the task is to determine the dynamic material properties of various polymer materials in a wide frequency range by testing materials at different temperatures. Within the assignment, it is necessary to: prepare samples for testing, perform DMA tests on a rotary rheometer at different temperatures, compose a master curve under the reference conditions using a frequency-temperature superposition, and compare the results between different polymer materials.

Additionally, it is necessary to use well-known mathematical models for modelling frequency-dependent material properties and to make a comparison between models in order to determine which of the models better predicts the properties.

Contact person: Assist. Prof. Dr. Lidija Slemenik Perše

Webpage of the laboratory: http://web.fs.uni-lj.si/cem/

Two of the most important selling points for products like dishwasher are their power consumption and final dryness of the kitchenware. The current dishwasher drying system heats water to a high temperature in the last washing step in order to increase temperature of the kitchenware and therefore increase drying process. However, this is not the most effective way, due to small mass of plastic kitchenware and as a resulting final dryness is not satisfying. Few options are available to improve current drying system, which will be evaluated in the thesis. The aim of this thesis is to define a completely new drying system for a dishwasher and experimentally characterize it with aim to satisfy the final dryness of kitchenware.

Prerequisite knowledge: basic programming knowledge

Contact person: Assist. Prof. Dr. Katja Klinar

Webpage of the laboratory: https://lahde.fs.uni-lj.si/en/home/

In recent years, a large amount of scientific papers focuses on additive manufacturing or 3D printing, due to reduced material costs and possibility to produce unusual complex geometries, as opposed to conventional technologies. However, the prediction of mechanical behaviour of such structures is difficult, since they possess on manufacturing parameters dependent, anisotropic properties. The goal of the thesis is to create and experimentally validate a mechanical model of the structure produced by fused deposition modelling. In order to achieve this goal, the student has to study the literature which tackled this problem and afterwards create appropriate analyitical/numerical model of the structure. In order to validate the model, an experiment has to be designed and created at the end.

Contact person: Prof. Dr. Janko Slavič

Webpage of the laboratory: http://www.ladisk.si/

Microfluidics deal with the flow of liquids inside micrometer-sized channels. In order to consider it microfluidics, at least one dimension of the channel must be in the range of a micrometer or tens of micrometers.

Although most microfluidic devices are based on continuous flow of liquids in microchanells,  there has  been an increasing interest for the past couple of years in devices that rely on manipulation of discrete droplets using surface tension effects. One such technique is ElectroWetting On Dielectric (EWOD), which is based on wettability of liquids on a dielectric solid surface by varying the electrical potential.

The focus of this research will be to develop electrohydrodynamic numerical model of EWOD mechanism. First objective is to model the change in the contact angle with surface of the droplet when the electric potential is applied or turned off. The electrowetting effect in the fluid flow dynamics will then be directly introduced through the equations from electrostatics and coupled with the Navier-Stokes equations, respectively. Namely, this transition to the fluid-electro-dynamics will be the second task of the electrohydrodynamic modelling. The main and final goal is to numerically analyze different geometries and electrical properties of electrodes and droplets, which will allow for a fast actuation of the droplets.

Contact person: Tch. Asst. Dr. Urban Tomc

Webpage of the laboratory: https://lahde.fs.uni-lj.si/en/home/

Experimental work to determine the optimal abrasive flow rate for two types of materials of several thicknesses at the given pressure and combination of water nozzle and focusing tube. The criteria is minimum machining costs. Higher abrasive flow rate enables higher machining speed, but also causes higher machining costs per working hour. The former relation is not linear whereas the latter is linear.

Contact person: Assoc. Prof. Dr. Joško Valentinčič

Webpage of the laboratory: http://www.fs.uni-lj.si/lat

One of the consequences of global warming is also an overheating of buildings which reflects in increase of ambient temperatures. In order reduce the energy needed for cooling, passive technologies accumulating the excess heat from the space by changing their phase are introduced. Phase change materials (PCM) can be applied on the external wall. However, due to material properties, there is a risk that the material without nighttime ventilation would not successfully discharge and released it latent heat. To enhance the performance/discharge the material completely, a strategy for air based active PCM is proposed called ‘ventilated layer’. The parametrical analysis of the ventilated layer (air velocity, flowrate, inlet diffusor, geometry of the system) will be studied with ANSYS Fluent.

Contact person: Assoc. Prof. Dr. Uroš Stritih

Webpage of the laboratory: http://lab.fs.uni-lj.si/los1/

One of the consequences of global warming is also an overheating of buildings which reflects in increase of ambient temperatures. In order reduce the energy needed for cooling, passive technologies accumulating the excess heat from the space by changing their phase are introduced. Phase change materials (PCM) can be applied on the external wall. However, due to material properties, there is a risk that the material without nighttime ventilation would not successfully discharge and released it latent heat. To enhance the performance/discharge the material completely, a strategy for air based active PCM is proposed called ‘ventilated layer’. The performance of such system will be tested with TRNSYS software where also a parametrical analysis of the mechanical components will be investigated.

Contact person: Assoc. Prof. Dr. Uroš Stritih

Webpage of the laboratory: http://lab.fs.uni-lj.si/los1/

In recent years, phase-based methods for displacement identification in digital images have substantially gained in popularity. State of the art approaches to phase-based motion identification are already considered a valid alternative to gradient-based methods (e. g. optical flow) also in vibration measurement applications. Combined gradient and phase-based approaches aim to extract as much motion information from high-speed digital video as possible, improving the signal-to-noise-ratio of image-based measurements. The goal of this thesis is to survey the available tools for spatiotemporal phase calculation in digital images within the Python framework and implement a phase-based displacement identification algorithm, as well as assess the possibility of extending this algorithm into a phase-based motion magnification application.

Contact person: Prof. Dr. Janko Slavič

Webpage of the laboratory: www.ladisk.si

Determination of formability limits is a crucial task in evaluation of sheet metal materials. For this purpose two main procedures are used: Nakazima test and Marciniak test. The Marciniak test should be evaluated in the presented master thesis.

In order to evaluate the strains on the sheet metal the optical system combined with Marciniak test exists in the Forming Laboratory. The test is currently used on pre-printed shapes. With upgraded picture detection and evaluation the strain distribution on random-distributed pattern should be evaluated. In the master thesis the tool for data acquisition and evaluation has to be build based on available image recognition tools.

Preliminary knowledge: programming skills, data acquisition, Labview

Contact person: Assoc. Prof. Dr. Tomaž Pepelnjak

Webpage of the laboratory: https://www.fs.uni-lj.si/laboratory/laboratorij-za-preoblikovanje-lap-2/

Thermal rectification is a phenomenon in which thermal transport along a specific axis is dependent upon the sign of the temperature gradient or heat current. Currently several mechanisms for thermal rectification have been proposed including surface roughness/flatness at material contacts, thermal potential barrier between material contacts, difference in temperature dependence of thermal conductivity between dissimilar materials at a contact, nanostructured asymmetry, anharmonic lattices and quantum thermal systems. The research is based on development of numerical model for characterization of thermal rectification in different materials and geometries.

Prerequisite knowledge: basic programming knowledge

Contact person: Assist. Prof. Dr. Katja Klinar

Webpage of the laboratory: https://lahde.fs.uni-lj.si/en/home/

Surface energy is relevant property of surfaces, since it defines the interaction of surface with surroundings, other surfaces, liquids, etc. Common approach to determine it is by contact angles measurements by employing different models is used. However this works well at ambient temperature, but he problems are at elevated temperatures. Namely, if we have temperature difference between model liquid (for wetting test) and surface as well as environment, in addition we have thermo-dynamic process which can significantly effect on wetting and thus on calculated surface energy. In this work, student will in first part study relevant literature for surface energies measured by contact angles at elevated temperatures in terms to get overall impression of current state of development, main issues and problems. In second part student will perform tests on contact angle goniometer, with heated samples and liquid and try to find correlation compared to measured values of contact angles as well as calculated surface energies at ambient conditions.

Contact person: Prof. Dr. Mitjan Kalin

Webpage of the laboratory: https://www.tint.fs.uni-lj.si/

Re-use of polymeric materials is important for sustainable development, where recycling plays an important role in reducing waste materials. However, some of the properties of polymer materials change with recycling. The aim of the task is to determine how multiple recycling affects the mechanical, thermal and rheological properties of HDPE material.

Contact person: Assist. Prof. Dr. Lidija Slemenik Perše

Webpage of the laboratory: http://web.fs.uni-lj.si/cem/

The use of several solid-lubricant nanomaterials as additives in lubricants present a promising new lubrication technology that combines the benefits of liquid lubrication with the physically based effect of nanoparticles. This would lead to a decrease in the toxic emissions and would eliminate the need for a tribochemical activation. In order to make such lubricants suitable for lubrication of various surfaces, e.g. DLC coatings, their tribological properties, such a friction and wear, need to be studied in detail.

Within the scope of this work the emphasis will be on the investigation of macro-lubrication behavior of graphene-based additives in oil as well as their tribological effects (friction and wear) on various contact configurations with steel and DLC coatings (steel/a-C:H and steel/a-C:H:Si).

Contact person: Prof. Dr. Mitjan Kalin

Webpage of the laboratory: https://www.tint.fs.uni-lj.si/

Short glass fibers in a thermoplastic polymer matrix improve the mechanical properties of the material (tensile strength, impact strength, …). The question is, however, how glass fibers affect the time dependent behavior of the composite material, especially if the composite material is exposed to moisture.

The aim of the task is to determine the long-term time-dependent mechanical properties of the composite material and to determine the influence of moisture on the time-dependent behavior of this composite.

Contact person: Assist. Prof. Dr. Lidija Slemenik Perše

Webpage of the laboratory: http://web.fs.uni-lj.si/cem/

Short glass fibers in a thermoplastic polymer matrix improve mechanical properties of the material (tensile strength, impact strength, …). The questions are, however, (i) how glass fibers affect the time-dependent behaviour of the composite material, (ii) what is the effect of increasing the fraction of the fibers on these properties, and (iii) how the fiber orientation affects time-dependent properties.

It is necessary to compare the time-dependent properties of a pure thermoplastic polymer with a composite material with different fiber orientations and fiber concentrations. Based on experimentally determined properties, it is necessary to propose a model, which would effectively predict such behaviour.

Contact person: Assist. Prof. Dr. Lidija Slemenik Perše

Webpage of the laboratory: http://web.fs.uni-lj.si/cem/

3D printed products are increasingly found in more demanding industries, such as: medicine, space technology, aerospace industry, etc. It is known that the manufacturing bowls can significantly influence the structure of the polymeric material and, consequently, its mechanical properties. The goal of the task is to determine the link between the production parameters (print speed, print temperature, cooling rate and substrate temperature) depending on the production parameters using neural networks. The required knowledge of neural networks is given to the candidate during the course of the task.

Contact person: Assist. Prof. Dr. Lidija Slemenik Perše

Webpage of the laboratory: http://web.fs.uni-lj.si/cem/

A phase change material (PCM) is a substance, which is capable of storing and releasing large amounts of energy and can serve as a latent heat storage system. Heat is absorbed or released when the material changes from solid to liquid phase and vice versa. For household appliances is important that material has strong supercooling effect, since this effects ability to store latent energy partly loss free up to 2 days or more.

The purpose of this research will be to theoretically analyse suitable PCM materials and experimentally characterize it at different conditions, to determine material stability and thermal properties. The candidate will try to simulate similar conditions in one or more household appliances to see how the system responds and how much energy could be recovered with implementation of PCM materials.

Prerequisite knowledge: basic programming knowledge

Contact person: Sr. Dev. Nada Petelin

Webpage of the laboratory: https://lahde.fs.uni-lj.si/en/home/