Papers by Eugene Nikiforovich
Exergy-based methods provide engineers with the best information with respect to op
tions for imp... more Exergy-based methods provide engineers with the best information with respect to op
tions for improving the overall thermodynamic efficiency of an energy conversion system. This pa
per presents the results of an advanced exergy analysis of an air-to-water reversible heat pump
whose performance was analyzed with respect to different working fluids. Environmentally dele
terious refrigerants, i.e., R410A and R134a (baselines), and their eco-friendly replacements (R290,
R152a, R1234ze(E), and R1234yf) were selected. The evaluations were conducted under the same
operating conditions (i.e., with the same cooling and heating demands and outdoor temperatures).
Based on conventional exergy analysis, it was determined that different priorities should be given
for the thermodynamic improvement of the components according to which heating and cooling
modes of the system are in use. Therefore, integrated parameters, i.e., the annual values of exergy
destruction, were applied for further analysis. The results obtained showed that the heat pump us
ing R410A provided the largest degree of annual exergy destruction estimated on the basis of con
ventional exergy analysis (5913 kWh), whereas the heat pump using R290 offered the lowest one
(4522 kWh). The annual exergy destruction of the R410A cycle with only unavoidable irreversibili
ties could be decreased by 50%. In this case, compared to R410A and R134a, R152a and R290 pro
vided lower values of the total annual unavoidable aspects of exergy destruction. Considering tech
nological limitations, when removing all the avoidable irreversibilities within the air exchanger, the
largest decrease in the total exergy destruction within the system could be reached. The results ob
tained from the analysis of the removable irreversibilities showed that the mutual interactions be
tween the compressor, evaporator, and condenser were weak. Finally, it was concluded that, from
a thermodynamic point of view, the adoption of R152a and R290 in reversible air-to-water heat
pumps as replacements for R410A and R134a is advisable.
Akademiia Nauk SSSR Doklady, 1989
ABSTRACT An asymptotic analysis of the initial system of Navier-Stokes equations is used to ident... more ABSTRACT An asymptotic analysis of the initial system of Navier-Stokes equations is used to identify different types of free convective flows corresponding to different types of small-parameter expansions. The small-parameter characterizes deviations of the density of the medium from the homogeneous state in the Boussinesq approximation.
36th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems (ECOS 2023)
Energies
Exergy-based methods provide engineers with the best information with respect to options for impr... more Exergy-based methods provide engineers with the best information with respect to options for improving the overall thermodynamic efficiency of an energy conversion system. This paper presents the results of an advanced exergy analysis of an air-to-water reversible heat pump whose performance was analyzed with respect to different working fluids. Environmentally deleterious refrigerants, i.e., R410A and R134a (baselines), and their eco-friendly replacements (R290, R152a, R1234ze(E), and R1234yf) were selected. The evaluations were conducted under the same operating conditions (i.e., with the same cooling and heating demands and outdoor temperatures). Based on conventional exergy analysis, it was determined that different priorities should be given for the thermodynamic improvement of the components according to which heating and cooling modes of the system are in use. Therefore, integrated parameters, i.e., the annual values of exergy destruction, were applied for further analysis. T...
This paper reflects on experiences of integrating sustainability in engineering education in Ukra... more This paper reflects on experiences of integrating sustainability in engineering education in Ukraine and discusses the personal contribution of Prof. Leo Jansen to this process. The authors argue that Ukrainian engineering universities are progressing in incorporating sustainability in their curricula. Major efforts are still needed to shift the focus of educational programs from awareness rising by teaching about sustainability challenges to discussions on how engineers can meet those challenges and how sustainability is coupled to students' main disciplines. The paper identifies several features of Ukrainian society that affect SD programs and that shall be taken into consideration while designing pedagogical approaches in engineering universities of the country. Among those factors are: -Civil society is in an infant stage of development in Ukraine; -Short-term planning is prevailing in the country; -There is scepticism among the wider public towards expert-focused strategic ...
International Journal of Sustainability in Higher Education, 2015
Purpose – This paper aims at identifying factors that could contribute to the motivation of stude... more Purpose – This paper aims at identifying factors that could contribute to the motivation of students in sustainable development (SD) education. The underlying idea of the paper is that SD education is not always as attractive among students and lecturers as many would like it to be. Design/methodology/approach – The paper briefly reviews literature regarding behavioral change for long-term benefits. It identifies four motivators that could be effective to make people pursue longer-term objectives. It identifies if these motivators were present in five cases of successful SD education. Findings – The four motivators for students that were identified in the literature review (a sense of autonomy, a challenge of reflection on the future role, connection with others, self-fulfillment, focus on the individual learning need) could be observed in the cases of successful SD education, although to various degrees. Individual autonomy in learning was not observed, but group autonomy was prese...
Sustainability Assessment Tools in Higher Education Institutions, 2013
ABSTRACT This chapter presents an overview of positive motivators for students, lecturers, and ed... more ABSTRACT This chapter presents an overview of positive motivators for students, lecturers, and educational managers to prioritize Sustainable Development in education. Very often, we implicitly assume that students and colleagues should all be motivated by the great challenges that the world faces. And if they appear not to react sufficiently to these challenges, we sometimes tend to give these challenges an apocalyptic character. But is this the right motivator for students and colleagues to work on Sustainable Development? We all know that if you only use a stick and no carrot… So why don’t we use more carrots? The bureaucracy that comes with tools for checking/auditing/evaluating the (SD content of) programs/curricula is not particularly a strong motivator for university lecturers. And building courses that add another subject to the erudition of the graduate might not be the right motivators for students that want to make a difference. We are often still in the process of convincing university managers to add SD to the curriculum, convincing colleagues to address SD, and convincing students to pick SD electives and address SD in their projects. How to motivate them to do this when this gives them no direct personal reward and even might increase their workload? The paper will explore options to develop motivating educating by reviewing case studies on educational renewal in four universities. It concludes that there are various options for more motivating education. However, to fully utilize these options, more priority should be given to education.
Applied Sciences, 2021
Avoidable endogenous/exogenous parts of the exergy destruction in the components of an energy con... more Avoidable endogenous/exogenous parts of the exergy destruction in the components of an energy conversion system can be computed by applying advanced exergy analysis. Their calculation is crucial for the correct assessment of the real thermodynamic enhancement achievable by the investigated energy conversion system. This work proposes a new approach to estimate the avoidable exergy destruction rates of system components, being more rigorous compared to the conventional method due to the elimination of the need for the implementation of theoretical assumptions associated with the idealization of processes. An open-source web-based interactive tool was implemented to contrast the results of the conventional advanced exergy analysis to those involving the new approach for avoidable exergy destruction estimation. The comparison was based on the same case study, i.e., a refrigeration system selected from the literature. It was observed that the developed tool can be properly employed for ...
34th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems (ECOS 2021)
34th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems (ECOS 2021)
The talk addresses the experimental, analytical and numerical modelling of the dynamics of concen... more The talk addresses the experimental, analytical and numerical modelling of the dynamics of concentrated vortex packets over a rigid smooth plane. To answer the principal question why and how does fluid in outer region of the turbulent boundary layer organize itself into hairpin streamwise vortex packets with low-speed convective velocity we developed the vortex filament model of hierarchy of hairpin packets.
Applied Sciences
Avoidable endogenous/exogenous parts of the exergy destruction in the components of an energy con... more Avoidable endogenous/exogenous parts of the exergy destruction in the components of an energy conversion system can be computed by applying advanced exergy analysis. Their calculation is crucial for the correct assessment of the real thermodynamic enhancement achievable by the investigated energy conversion system. This work proposes a new approach to estimate the avoidable exergy destruction rates of system components, being more rigorous compared to the conventional method due to the elimination of the need for the implementation of theoretical assumptions associated with the idealization of processes. An open-source web-based interactive tool was implemented to contrast the results of the conventional advanced exergy analysis to those involving the new approach for avoidable exergy destruction estimation. The comparison was based on the same case study, i.e., a refrigeration system selected from the literature. It was observed that the developed tool can be properly employed for ...
ABSTRACT The paper presents a new approach to the study of Görtler vortices effected by centrifug... more ABSTRACT The paper presents a new approach to the study of Görtler vortices effected by centrifugal forces. It allows to extend the knowledge of the flow dynamics to the boundary layers under different body forces. The main idea consists of the following: From the common sense point of view, it is obvious that all specific features of boundary-layer development over a curved surface compared to the flat plate (for instance, Blasius boundary layer) must depend explicitly on a small parameter related to the curvature. Mathematically this means that the problem is singularly disturbed by this small parameter. Hence, using the method of matched asymptotic solutions, one can obtain the equation systems for corresponding expansions of an unknown solution valid for certain flow domains and determine spatial scales for these domains depending on the basic flow parameters. Physically these domains represent flow zones with essentially different dynamical structure and space characteristics. The study of asymptotic and group properties of the equation systems describing fluid motion in various flow domains give the knowledge of formation mechanisms of 3D vortical structures in boundary layers, (2) downstream distance expressed through the basic flow parameters where 3D structures may arise, and (3) spatio-temporal properties of 2D and 3D vortical structures depending on basic parameters.
This paper discusses challenges of capacity building in sustainable urban energy planning and dev... more This paper discusses challenges of capacity building in sustainable urban energy planning and development in Western Balkan Countries (WBC). It identifies needs in training of municipal staff and addresses obstacles for transferring sustainable energy education from EU universities to universities of WBC. The analysis of the ten training courses developed and piloted in collaboration with academic and non-academic stakeholders in Bosnia and Herzegovina, Montenegro and Serbia shows that while international cooperation has a good potential to improve quality of capacity building and to catalyse university-society collaboration in WBC, significant efforts on national and local (university) levels are needed to fully capitalise on these opportunities. In particular, it is necessary to enhance an interdisciplinary approach to education in sustainable energy, incorporating economic, social and institutional aspects of energy production and consumption together with the technical ones. On ...
Joint Course in Sustainable Development at Kiev Polytechnic Institute : an example of cooperation... more Joint Course in Sustainable Development at Kiev Polytechnic Institute : an example of cooperation among 4 European universities
The paper describes and analyses a participatory backcasting teaching toolbox (PBTT) designed to ... more The paper describes and analyses a participatory backcasting teaching toolbox (PBTT) designed to develop a set of skills required for sustainability change agents, including critical and systems thinking, future orientation, ability to work in transdisciplinary frameworks, personal involvement, conflict resolution and consensus building, dealing with complexity and uncertainty, creativity, practical problemsolving and action skills. The PBTT has evolved through experience and insights gained from the implementation of participatory backcasting (PB) methodology within two research projects and from three years of PB teaching practices. The PBTT includes twelve modules based on different steps and procedures of the PB process. The paper describes effects of the PBTT on the development of students’ skills that have been observed throughout ten teaching cases. Furthermore, the potentials and limitations of the PBTT for building up the sustainable development related skills are discussed.
This paper reflects on experiences of integrating sustainability in engineering education in Ukra... more This paper reflects on experiences of integrating sustainability in engineering education in Ukraine and discusses the personal contribution of Prof. Leo Jansen to this process. The authors argue that Ukrainian engineering universities are progressing in incorporating sustainability in their curricula. Major efforts are still needed to shift the focus of educational programs from awareness rising by teaching about sustainability challenges to discussions on how engineers can meet those challenges and how sustainability is coupled to students’ main disciplines. The paper identifies several features of Ukrainian society that affect SD programs and that shall be taken into consideration while designing pedagogical approaches in engineering universities of the country. Among those factors are: Civil society is in an infant stage of development in Ukraine; Short-term planning is prevailing in the country; There is scepticism among the wider public towards expert-focused strategic develop...
ABSTRACT Vortical structure generation is one of important problems in geophysics. At present, th... more ABSTRACT Vortical structure generation is one of important problems in geophysics. At present, the generation of large-scale structures of typhoon type in the presence of helical turbulence has been studied well enough (Moiseev et al., 1983). On the other hand, until now the influence of topology on these processes has been studied insufficiently. Here we consider the influence of large-scale Earth surface topology on the origination of mesocyclones. In the present paper we dwell on possible geophysical effects connected with generation of longitudinal helical vortices in the vicinity of concave surfaces with a relatively long radius of curvature.
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Papers by Eugene Nikiforovich
tions for improving the overall thermodynamic efficiency of an energy conversion system. This pa
per presents the results of an advanced exergy analysis of an air-to-water reversible heat pump
whose performance was analyzed with respect to different working fluids. Environmentally dele
terious refrigerants, i.e., R410A and R134a (baselines), and their eco-friendly replacements (R290,
R152a, R1234ze(E), and R1234yf) were selected. The evaluations were conducted under the same
operating conditions (i.e., with the same cooling and heating demands and outdoor temperatures).
Based on conventional exergy analysis, it was determined that different priorities should be given
for the thermodynamic improvement of the components according to which heating and cooling
modes of the system are in use. Therefore, integrated parameters, i.e., the annual values of exergy
destruction, were applied for further analysis. The results obtained showed that the heat pump us
ing R410A provided the largest degree of annual exergy destruction estimated on the basis of con
ventional exergy analysis (5913 kWh), whereas the heat pump using R290 offered the lowest one
(4522 kWh). The annual exergy destruction of the R410A cycle with only unavoidable irreversibili
ties could be decreased by 50%. In this case, compared to R410A and R134a, R152a and R290 pro
vided lower values of the total annual unavoidable aspects of exergy destruction. Considering tech
nological limitations, when removing all the avoidable irreversibilities within the air exchanger, the
largest decrease in the total exergy destruction within the system could be reached. The results ob
tained from the analysis of the removable irreversibilities showed that the mutual interactions be
tween the compressor, evaporator, and condenser were weak. Finally, it was concluded that, from
a thermodynamic point of view, the adoption of R152a and R290 in reversible air-to-water heat
pumps as replacements for R410A and R134a is advisable.
tions for improving the overall thermodynamic efficiency of an energy conversion system. This pa
per presents the results of an advanced exergy analysis of an air-to-water reversible heat pump
whose performance was analyzed with respect to different working fluids. Environmentally dele
terious refrigerants, i.e., R410A and R134a (baselines), and their eco-friendly replacements (R290,
R152a, R1234ze(E), and R1234yf) were selected. The evaluations were conducted under the same
operating conditions (i.e., with the same cooling and heating demands and outdoor temperatures).
Based on conventional exergy analysis, it was determined that different priorities should be given
for the thermodynamic improvement of the components according to which heating and cooling
modes of the system are in use. Therefore, integrated parameters, i.e., the annual values of exergy
destruction, were applied for further analysis. The results obtained showed that the heat pump us
ing R410A provided the largest degree of annual exergy destruction estimated on the basis of con
ventional exergy analysis (5913 kWh), whereas the heat pump using R290 offered the lowest one
(4522 kWh). The annual exergy destruction of the R410A cycle with only unavoidable irreversibili
ties could be decreased by 50%. In this case, compared to R410A and R134a, R152a and R290 pro
vided lower values of the total annual unavoidable aspects of exergy destruction. Considering tech
nological limitations, when removing all the avoidable irreversibilities within the air exchanger, the
largest decrease in the total exergy destruction within the system could be reached. The results ob
tained from the analysis of the removable irreversibilities showed that the mutual interactions be
tween the compressor, evaporator, and condenser were weak. Finally, it was concluded that, from
a thermodynamic point of view, the adoption of R152a and R290 in reversible air-to-water heat
pumps as replacements for R410A and R134a is advisable.