Projects / Programmes
Research in Power, Process, and Environmental Engineering
January 1, 2015
- December 31, 2019
| Code |
Science |
Field |
Subfield |
| 2.13.00 |
Engineering sciences and technologies |
Process engineering |
|
| 1.08.00 |
Natural sciences and mathematics |
Control and care of the environment |
|
| Code |
Science |
Field |
| T210 |
Technological sciences |
Mechanical engineering, hydraulics, vacuum technology, vibration and acoustic engineering |
| Code |
Science |
Field |
| 2.03 |
Engineering and Technology |
Mechanical engineering |
Computational fluid dynamics, Boundary element method, Turbulent flow, multiphase flow, dispersed flow, reactive flow, heat and mass transfer, combustion, turbomachinery, internal combustion engines, incineration, drying, heating, ventilation, air conditioning
Researchers (22)
Organisations (3)
Abstract
The basic scientific theoretical tenets of proposed engineering research program are transport phenomena in solids and fluids, i.e. transport of momentum, heat, and mass with prevalent turbulent fluid flow characteristics. The main research method is the computational fluid dynamics (CFD), which enables closer look into differential spatial and temporal process development taking advantage of derivation of appropriate models for transport phenomena calculations in devices and machines. Research group has proprietary computational tools for 3D unsteady transport phenomena in solids and fluids at its disposal, which are based on Boundary Element Method (BEM) and provides for simulation of fluid flows as well as heat and mass transfer. For simulations in the area of process engineering so called fast BEM will be developed with emphasis on high accuracy of nonlinear problem computations. In the area of heterogeneous systems diffusion models of heat and mass transfer in porous media will be upgraded using two phases, flow through nanofluid saturated porous media will be analysed as well as models of multi phase flow in porous media. Own BEM programming tool will be upgraded with models for numerical simulation of dispersed flows which will be based on accurate transfer of influences between particle and fluid by using fundamental solutions justified by physics. Development of hybrid models of turbulent flows will focus on development of new models of connections between advanced non-stationary URANS models (2nd generation URANS) and LES with special emphasis on soft interface URANS-LES. Fluid flow will be also simulated using direct numerical simulation (DNS) and influences of particles characteristics such as size, shape, inertia, buoyancy, density on motion in flow will be studied. Analysis of water turbomachinery will be focused on transient flow conditions (start, overspeed). By applying multicriteria optimization we will investigate the efficiency in multitude of operation points and also cavitation characteristics of water turbines. In the area of turbo compressors, turbofans and fans the research will focus on conditions for onset of characteristic stall hysteresis. The goal of the research is explanation of mechanisms of onset and development of stalling malfunction, determination of influence factors and finding of corrective measures. In the area of internal combustion engine we will study the influence of use of various alternative fuels in engines with spontaneous combustion, determined characteristics of test engine by using alternative fuel and optimize the construction and regulation parameters of engine depending on minimum production of harmful emissions. In the area of reactive flows in devices for thermal use of solid waste we will expand the multi-sectoral equilibrium model for the description of the main mechanisms of gas-solid transition in terms of combustion on the grate with respect to porosity of layer on the grate.
Significance for science
Understanding and ability of prediction of characteristics of technical systems with prevailing turbulent and multiphase flows is based on deeper knowledge of transport phenomena in these flows. The development of new and accurate methods of computer based simulations of transport phenomena, which greatly exceed the quality of results of classical, on empirical realizations based engineering calculations, is therefore of prime importance for the further development of engineering sciences in the field of power, process and environmental engineering.
In the field of development of new numerical methods in the framework of the Boundary Element Method we anticipate results that will lead to decrease of computational times and required computer memory when computing cases with dense computational grids, which are necessary for a realistic description of flow fields. The development of advanced models for heat and mass transfer in dispersed flows will lead to a detailed insight into complex flow, temperature and component (species) fields in heat nad mass transfer separation devices (dryers) as well as internal combustion (IC) engines. A detailed physical understanding of multiphase turbulent flows in mechanical as well as process engineering will lead to a better understanding of operations of devices, where interaction of turbulent structures and dispersed phase is not fully understood yet. In the field of the use of numerical methods for computation of flows in turbomachinery the scientific focus is on the study of transient and cavitating flows. With this we enrich our knowledge of different stable (partial loading, optimal working point, full power) as well as unstable operating regimes (start, runaway). Research in the field of turbo compressors in the stall regime is currently limited to studies of inflow and outlet of the rotor, whereas the attempts to experimentally determine the conditions inside the blade channels are still rare. The mechanisms of onset and developent of stall are still not satisfactory described, and solutions are mainly based on detection and consequent due measures, and less on prevention, which can be achieved by a suitable geometry definition, which is one of our goals. Based on increasingly rigorous environmenal legislation and the problems in the use of fossil fuels there exist a need to search for new methods of use of alternative fuels in internal combustion engines. The newly developed mathematical models for numerical simulation of injection process and combustion will reduce excessive experimental testings and enable a faster development of more efficient and environmentally friendly IC motors. The development of equilibrium model of multistage gasification of solid waste on a grate will enable a more detailed analysis of combustion characteristics in primary and secondary chamber in the dvice for thermal use of solid waste.
Significance for the country
Process engineering and pharmaceutical industry shows large needs for numerical modelling of transport phenomena in dispersed phase of solid particles. As application example of spray drying of solid particles in flow of continuous fluid will be used (drying air) with three stage drying with better forecasting of energy used of this energy wasteful process. This will be continued with use of research in numerical field with heat transfer models development of car lightnings, in particular as Slovenia already features two important manufacturers, one of which (Hella Saturnus) already cooperates with members of our research group.
Water power is the most important among of renewable energy resources without CO2 footprint. Slovenia has a long lasting tradition as well as plethora of knowledge and experience in developing and manufacturing of water turbines with emphasis on Turboinštitut, our partner in research program. If results are to be used in the market one need exceptional characterics of machines and reduction of cost. Both can be achieved with development of new numerical methods with better description of turbines. There are also number of smaller projects where physical models manufacturing does not justify the cost so the only alternative really is numerical check of requested characteristics. Internships by students from Maribor and Ljubljana provides for popularity of numerical methods in industry, and at the same time results in diploma, master theses and doctoral dissertations in the area of numerical analysis of hydraulic machinery flows.
Compressors, and in particular fans, are built into several types of products manufactured by our companies, from manufacturers of small household appliances, car parts as well as large refrigeration systems. Geometry of fans depends on final form of a product, this often resulting in inappropriate form of fan housing geometry and as such not optimum, with fan operation on the brink of stagnation, and this can be avoided by better understanding of flow characteristics. Such approach will improve the products, and this should have impact on Slovenias economic development.
Heating, cooling and climatization (HVAC) will be focused on optimization of efficiency of convection heating with taking into account outside and inside temperatures for each heating unit, in particular in residential and business buildings.
Environmental engineering research will focus on development of methods of heat treatment of waste and analysis of fuel suitability, said fuels manufactured from household waste. By addressing the issue we will contribute to better Slovenia's treatment of this waste. Multiphase numerical methods will be used for study of biological systems (treatment plants) as microorganisms in these flows usually behave as particles. In case of ground water numerical methods will be used for simulation of transport of pollutants in ground water.
Most important scientific results
Annual report
2015,
interim report,
final report
Most important socioeconomically and culturally relevant results
Annual report
2015,
interim report,
final report
