Viktor Mileikovskyi
@knuba.edu.ua
Professor of Heat-Gas Supply and Ventilation Department
Kyiv National University of Construction and Architecture
RESEARCH INTERESTS
Air distribution
CFD
Colebrook-White equation
Cooling Effect of Plants
Energy Plus Building
Film Heat Exchanger
Gas Exchange in Plants
Green Roof
Green Structures
Green Wall
Heat Recovery
Heat-Mass Exchange
Heat-mass transfer in green structures
HVAC
IAQ
Indoor Plants
NZEB
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Maryna Kravchenko, Grzegorz Wrzesiński, Katarzyna Pawluk, Marzena Lendo-Siwicka, Anna Markiewicz, Tetiana Tkachenko, Viktor Mileikovskyi, Olga Zhovkva, Sylwia Szymanek, and Konrad Piechowicz
MDPI AG
Implementing rain garden (RG) designs is widespread worldwide to reduce peak flow rates, promote stormwater infiltration, and treat pollutants. However, inadequate RG design degrades its hydrological behaviour, requiring the development and validation of an appropriate hydrological model for the design and analysis of structures. This study aimed to improve a hydrological infiltration model based on Darcy’s law by taking into account the height of the water column (HWC) at the surface of the RG and the filtration coefficients of soil materials. The model was tested by simulating the hydrological characteristics of a rain garden based on a single rain event of critical intensity (36 mm/h). Using the validated model, design curves were obtained that predict the performance of the RG as a function of the main design parameters of the structure: water column height, ratio of catchment area to structure area, layer thickness, and soil filtration coefficient. The hydrological efficiency of the RG was evaluated in terms of the time of complete saturation, filling of the structure with water, and determining the change in HWC caused by changes in the parameters. The filtration coefficient and thickness of the upper and intermediate infiltration layers of the RG are the main parameters that affect the depth of saturation of the layers of the structure and the HWC on the surface. The model is not very sensitive to the model parameters related to the lower gravel layer. If the top layer’s thickness increases by 10 cm, it takes longer to fill the structure with water, and the HWC on the surface reaches 0.341 m. The rain garden’s performance improves when the filtration coefficient of the top layer is 7.0 cm/h. Complete saturation and filling of the structure with rainwater do not occur within 7200 s, and the water column reaches a height of 0.342 m at this filtration coefficient. However, the rain garden’s effectiveness decreases if the filtration coefficient of the upper and intermediate layers exceeds 15 cm/h and 25 cm/h, respectively, or if the catchment area to RG area ratio decreases to values below 15. The modelling results confirm that considering the HWC in RG hydrological models is essential for designing structures to minimise the risk of overflow during intense rainfall events.
Maryna Kravchenko, Yuliia Trach, Roman Trach, Tetiana Tkachenko, and Viktor Mileikovskyi
MDPI AG
The expansion of impervious areas in the context of climate change leads to an increase in stormwater runoff. Runoff from roads, petrol stations, and service stations is the most common form of unintentional release of petroleum hydrocarbons (PHs). Rain gardens are an important practice for removing PHs from stormwater runoff, but little data exist on the removal efficiency and behaviour of these substances within the system. The main objective of the study is to investigate the effectiveness of rain gardens in removing pollutants such as diesel fuel (DF) and used engine oil (UEO) in a laboratory setting, as well as to study the behaviours of these pollutants within the system. Eight experimental columns (7.164 dm3) were packed with soil (bulk density 1.48 kg/dm3), river sand (1.6 kg/dm3), and gravel. Plants of the Physocarpus opulifolia Diabolo species were planted in the topsoil to study their resistance to PHs. For 6 months, the columns were watered with model PHs followed by simulated rain events. The concentrations of PHs in the leachate and soil media of the columns were determined by reverse-phase high-performance liquid chromatography (RP-HPLC). The results of HPLC indicated the absence of UEO and DF components in the leachates of all experimental columns, which suggested 100% removal of these substances from stormwater. The chromatography results showed that 95% of the modelled PHs were retained in the surface layer of the soil medium due to the sorption process, which led to a change in hydraulic conductivity over time. Recommendations are proposed to increase the service life of rain gardens designed to filter PHs from stormwater.
Maryna Kravchenko, Yuliia Trach, Roman Trach, Tetiana Tkachenko, and Viktor Mileikovskyi
MDPI AG
Rain gardens are used to solve urban problems related to the negative impact of stormwater. (1) Scientific contributions from different countries provide general guidelines for the design and operation of rain gardens in different geographical areas. Given the small spatial scale of rain gardens, the use of existing infiltration models often leads to design errors. (2) The purpose of this paper is to develop a hydrological model by introducing a system of equations that extends the ability to calculate the rate, flow rate and time of saturation of layers with moisture and rainwater leakage from the rain garden system. (3) The results obtained allow us to describe the dynamic processes of passage and saturation of layers of the rain garden at a certain point in time, which extends the ability to calculate the flow rate. It was established that the smaller the area of the rain garden compared to the area of the catchment basin, the faster it reaches its full saturation. Increasing the thickness of the rain garden layers allows for an increase in the efficiency of water retention at a lower value of the area ratio. (4) The practical significance of the results obtained is especially important for the correct description of hydrodynamics in the system and determining the optimal conditions for the effective functioning and management of the rain garden structure for any climatic region.
Daria Vakulenko, Tetiana Tkachenko, Viktor Mileikovskyi, Viktoriia Konovaliuk, and Oleksandr Liubarets
Latvia University of Life Sciences and Technologies, Faculty of Engineering and Information Technologies
There are a lot of devices, including rural equipment with a high level of tightness. Nowadays, a wide range of methods are used for investigation and testing: capillary, radiographic, radio wave, mass spectrometric, eddy current, surface-active substances, etc. These methods require special equipment and do not allow continuous monitoring during operation. The traditional soap solution coating can continuously monitor the tightness until drying. Thus, there is a problem in creating an easy and robust method of monitoring the tightness of the critical equipment parts during the operation. In this work, a new method for the tightness control is proposed. It is based on the principle of distributing flows in parallel piping. If the camera around a critical part is sealed, its leaks will have high aerodynamic resistance. Therefore, if a small hole (0.1-1 mm) is made in such a camera, its aerodynamic resistance will be some order smaller. Since the distribution of flows is inversely proportional to the square of the specific characteristic of aerodynamic resistance, the main outflow or inflow due to leakages in the critical part inside the camera will occur almost through this hole, which is easy to register. This camera has been used in the Laboratory of Heat-Mass Exchange in Green Structures to test gas exchange in plants. For testing the method, the fan in the test stand before final sealing is slowly accelerated until the signal appears. After that, the flow rate has been estimated using a collector. The results show a very high sensitivity. In the collector, the anemometer showed only 0.02 m·s-1. The confidence interval of the flow is 0-0.019 m3·h-1. However, the anemometer reading near the hole is 0.43, which is a very clear signal. The signal will be clear at the leakage of 0.0086 m3·h-1. The soap coating of all junctures and smoke visualisation did not show a leakage place. This allows recommending the camera for the most critical equipment parts.
Daria Vakulenko, Viktor Mileikovskyi, Tetiana Tkachenko, and Oleksandr Liubarets
Latvia University of Life Sciences and Technologies, Faculty of Engineering and Information Technologies
Thermal insulation of pipelines finds application across various industries, including agricultural technologies. The energy efficiency hinges on minimizing heat losses. The task is primarily achieved through effective heat insulation. Decentralized ventilation systems prove to be efficient in rural low-rise constructions. Among these, regenerative ventilators like Blauberg Vento/Vents TwinFresh stand out. There exists a goal to enhance their operational efficiency, which involves ongoing investigation into heat recovery processes within their thin ducts. Improving the insulation of the experimental setup leads to a reduction in experimental uncertainty. Also, a new gas exchange camera for CO₂ exchange in plants requires very low uncertainty of airflow measurements requiring very high precision of air density measurement. However, heat losses can influence the air temperature deviation in a flow meter. However, within the realm of heat transfer literature, the concept of the critical insulation radius is stated. Increasing the insulation radius beyond a certain point might diminish its efficacy due to outer surface development. Theoretical assumptions posit a constant heat transfer coefficient for the outer surface. Previously, we analysed the critical radius of horizontal cylinder pipes. This study deals with laminar convective flow around the outer vertical cylindrical insulation surface. Employing a formula considering the Grashof number, the average heat transfer coefficient is analysed. The results indicate that increasing insulation thickness reduces the surface temperature and the heat transfer coefficient such as for vertical pipes. An analysis of the thermal resistance function concerning the ratio of outer to inner diameters, and its derivative, was conducted. The asymptotic increase in the thermal resistance was found. This fully disproves the critical radius concept opening new perspectives on energy efficiency and thermotechnical research precision.
Tatiana Tkachenko, Maryna Kravchenko, Olena Voloshkina, Viktor Mileikovskyi, Oleksii Tkachenko, and Rostyslav Sipakov
American Society of Civil Engineers
T Tkachenko, V Mileikovskyi, V Konovaliuk, M Kravchenko, and I Satin
IOP Publishing
Abstract Phytofiltration is the most sustainable way to achieve a better quality of inlet air in buildings in a polluted environment. But they don’t take into account the biorhythms of plants and pollute the inlet air with CO2 during breathing only time. We collected and analysed data about the biorhythms of plants. As a result, a new bi-directional phytofilter was offered for cleaning and oxygenation of the inlet ventilation air, and also to protect the environment by cleaning the exhaust air from different pollutants. The device has spaces with shifted illumination rhythms and a valve system. A controller directs the inlet air to the space(s), where plants release CO2. The outlet air runs through other spaces. Literature data show that in the less favourable case, the CO2 and oxygen emissions are balanced per day without overall CO2 gain to the environment. When plants are growing, they sequestrate CO2 to catch greenhouse gas emissions. Either natural light, artificial light, or a combination of the two can be used. While the second option simply demands one plant metabolism type, the first option needs a combination of CAM metabolism and other plants
Tetiana Tkachenko, Viktor Mileikovskyi, Maryna Kravchenko, and Viktoriia Konovaliuk
IOP Publishing
Abstract To avoid ecological catastrophe, most cities are moving toward green building. The critical component is greening – conventional and green structures. Urban agriculture is a very prospective direction. Green roofs, terraces, and rooftop greenhouses are the most promising places for growing. This solves multiple tasks: heat loss recovery for planting (for rooftop greenhouses), additional thermal insulation, optimized logistics, increasing pollinator populations, avoiding pests, etc. In different-height districts, there are problems with natural illumination and winds. No good urban wind theory has been developed. The winds can be simulated in CFD software using a 3D model of a district. Most of the software can simulate solar radiation for thermotechnical calculations only. It should be simulated in other special software. The approach to calculating solar radiation is proposed using CFD software without additional needs. The unique "integrator" material should be added to the engineering database. Its thermotechnical properties can be set to obtain a temperature numerically equal to the exciting parameter. Application is shown in an example of a different-height building with a green roof. The results show areas most favorable for growing photophilous and shade-tolerant plants and placing cleaning and phytoncidal plants for maximum air quality in stagnation zones.
Daria Vakulenko, Viktor Mileikovskyi, Tetiana Tkachenko, Adam Ujma, and Viktoriia Konovaliuk
Latvia University of Life Sciences and Technologies, Faculty of Engineering
Thermal insulation of pipelines is used in different industries including agricultural technologies. Energy efficiency depends on heat losses, which, in turn, are limited by heat insulation. Decentralized ventilation is effective in rural low-rise buildings. One such device used is a regenerative ventilator like Blauberg Vento or Vents TwinFresh. There is a task to improve the efficiency of its operation. Investigation of heat recovery processes in thin ducts is taking place. Experimental uncertainty decreases with better heat insulation of the experimental setup. But in heat transfer literature, there is a notion of the critical radius of insulation. More the insulation radius should decrease its effectiveness due to the development of the outer surface. In the theory, the heat transfer coefficient of the outer surface is assumed to be constant. In this study, laminar convective flow around the outer horizontal cylindrical insulation surface of a large thickness is considered. The formula of the average heat transfer coefficient is used that takes into account the Grashof number. While the insulation thickness is increased, the surface temperature and the heat transfer coefficient are decreased. The function of thermal resistance dependence on the outer diameter related to the inner one and its derivative have been analysed. As a result, an asymptotic increase of thermal resistance was observed without extremums. So, there are no critical diameters if the insulation is so large to obtain laminar convective flow. The maximum radius of thermal insulation should be determined not as critical, but as expedient. Thus, it can provide 5-20% lower heat transfer resistance than the asymptotic one. The radius of thermal pipe insulation of technological devices should be accepted based on technical and economic justification.
Tetiana Tkachenko, Viktor Mileikovskyi, Ihor Satin, and Adam Ujma
Latvia University of Life Sciences and Technologies, Faculty of Engineering
In 2019, 99% of people in the world lived in areas violating WHO’s recommended air quality indicators. By WHO’s estimation, in 2019, air pollution caused 4.2 million premature deaths worldwide. The most harmful are PM2.5 particles, which penetrate the blood through the aerogematic barrier causing cardiovascular and respiratory diseases and cancer. PM10 can pass deeply into the lungs, but they are not so harmful. People always believed that rural air is healthy. Research at the University of Minnesota showed that 18 000 Americans die every year due to air pollution by agriculture, primarily, ammonia (NH3) from the decomposition of fertilizers and livestock waste (12.4 thousand deaths), and PM2.5 particles (4.8 thousand deaths). In polluted areas, plants have more aggressive allergenic pollen. Agricultural waste management and optimization of landscapes are effective ways of solving the problem. In this work, solutions are proposed to improve the air safety of agrocenoses. Minimization of contact of waste with air and its utilisation as soon as possible allows for avoiding decomposition. Converting to gasification boilers/ovens avoids releasing PM2.5 by heating. In addition, plants capable of purifying the air from relevant pollutants should be introduced in agrocenoses. The places for planting are forest protection strips, free places near roads, residential and administrative buildings, etc. In particular, the use of hedges with such plants can provide a local oasis of clean air around houses. In the case of dense land use and lack of free space, it is possible to introduce “green structures” on buildings. An assortment of plants for different regions of Ukraine is offered.
Tetiana Tkachenko, Viktor Mileikovskyi, Anna Moskvitina, Iryna Peftieva, Viktoriia Konovaliuk, and Adam Ujma
Latvia University of Life Sciences and Technologies, Faculty of Engineering
Today greenhouses are transformed. In the middle of the past century, they were almost glazing buildings above the ground. Due to the development of planting technologies, including mats or trays with substratum, aero – and hydroponics, etc., greenhouses now can be anywhere, including underground. This gives impetus for urban agriculture with optimal logistics (growing near consuming). Indoor green structures become more and more popular. The illumination of them is very important because plants lose decorative properties in unfavourite conditions. At the beginning of this century, there was an analysis of a lot of failed attempts to create winter gardens on underground floors. The illumination was calculated successfully by today’s norms, but the plants withered. This is because the norms were developed for natural-illumination greenhouses. Usually, the illumination is measured in lux or μmol/day. The first unit is weighted by wavelength according to the people’s eyes sensitivity. The second one accumulates all photons. But the plants have another photosynthetic activity curve. They use two photosynthetic substances – chlorophyll and beta-carotenoid (active on the green light). The chlorophyll changes its absorption curves dependent on solvent presence (a and b). This allows some variability for adapting to the light spectrum, which is used by water plants. Thus, both units do not apply to artificial illumination. In this work, we analyse the curves of solar and phytolamp spectrums, averaged sensibility and spectral luminous efficiency for photopic vision. Integration of the curves allows recalculation of the lux-meter reading to the equivalent solar illumination or the last one to the phytolamp power. We propose a new unit system – phytocandela-phytolumen-phytolux – according to the photosynthesis efficiency curve that is numerically equal to candela-lumen-lux under sunlight. This shows that lux may not be a base unit because it is related to a single biological species but not a physical property.
Tetiana Tkachenko, Olena Voloshkina, Viktor Mileikovskyi, Rostyslav Sipakov, Roman Hlushchenko, and Oleksii Tkachenko
American Society of Civil Engineers
Viktor Mileikovskyi and Tetiana Tkachenko
Springer International Publishing
Roman Hlushchenko, Tetiana Tkachenko, Viktor Mileikovskyi, Vasyl Kravets, and Oleksii Tkachenko
Stowarzyszenie Menedzerow Jakosci i Produkcji
Abstract Rainwater management is one of the important problems of cities. At very strong downpours, storm sewer systems may not capture the rainwater, which floods pavements and roadways. The water flushes fuel and oil traces after vehicles, fallen debris, and other pollutants, which will be moved to the ground, ponds, rivers, seas, etc. In past, the problems were solved using engineering approaches – a set of rainwater receivers, a duct network, and at best, wastewater treatment plants. Now, the sponge city concept is a better solution that uses a biotechnological way for throttling water flows, drainage, and purifying them. The work aims to improve the design of roads to fully absorb rainwater from them with maximum convenience for road users. We propose a design of roads using special “green structures” – rain-garden bands along the sides of roadways. We tested its ability of water capturing on the example of Kyiv city by matching the ability with the strongest precipitation observed. In addition, the proposed plants can extinguish the energy of bouncing cars during road accidents for the protection of pavements.
Tetiana Tkachenko and Viktor Mileikovskyi
IOP Publishing
AbstractFor carbon neutrality of cities, we should compensate carbon dioxide gains from vehicles. Human-driven ones are not carbon-free because cyclists perform hard work. Green roofs are an adequate carbon-capturing facility, especially for the dense building. We used the previous author’s data for carbon dioxide sequestration of them. The carbon dioxide gained from a cyclist is calculated using aggregated indicators for hard work and rest. Also, the experimental data for a cyclist on an exercise bike is used as an alternative. For recumbent bicycles, drag is 0.2÷0.3 of drag for classical ones. This allows estimation of the carbon dioxide gain for this promising technology. The results show that road bicycles require only 4.4 m2of extensive and 1.37 m2of intensive green roofs per cyclist. Recumbent bicycles need two-time fewer areas. Electric public conveyances and cars require one-two order of magnitude more area.
S Abu Deeb, T Tkachenko, and V Mileikovskyi
IOP Publishing
Abstract Protective forest plantations (PFP) play an essential functional role in the operation of anthropogenic landscapes (AL). A study of processes in the system “PFP-AL” was conducted in the Boguslav agroforestry state, Kyiv region, Ukraine, to maintain sustainability. A method of ecological monitoring has been proposed to achieve environmental equilibrium stability. The calculations show the stable state of the ecosystem. A graphic-analytical method for quantitative assessment of the potential adverse effects of natural resource management has been proposed. It is shown that additional compensation of adverse effects is necessary, which can be performed by green structures.
Tetiana Tkachenko and Viktor Mileikovskyi
Springer International Publishing
Viktor Mileikovskyi and Tetiana Tkachenko
Springer International Publishing
Tetiana Tkachenko and Viktor Mileikovskyi
EDP Sciences
Low air quality is one of the most widespread reasons for diseases of respiratory, cardiovascular, immune, and nervous systems. The work aims to improve indoor air quality using the most natural method – indoor phytoncide plants. R. Koch’s sedimentation method has been used. The rule of V. L. Omelianskyi calculated the total viable number. Phytoncide activity was estimated by tests of leaf disks in Petri dishes with evenly seeded microbes. Researches in a high school showed a very high total viable number after studies – up to 6000 CFU/cm3. Tests of leaf disks allowed ranging the commonly used indoor plants by phytoncide activity. The most active large-size plants are Citrus limon and Ficus benjamina. From small-size plants, Azalea and Fuchsia were recommended. Amaryllis and Phoenix dactylifera have the lowest phytoncide activity. Final tests of indoor air showed the possibility of decreasing the total viable number in the high school rooms 2.5-3.5 times.
T Tkachenko, V Mileikovskyi, V Dziubenko, and O. Tkachenko
IOP Publishing
Abstract To improve the safety in common areas of multi-storey buildings (lift halls, common corridors), it is proposed to renovate interiors of the areas. Such areas usually have no permanent ventilation. Thus, they can accumulate pathogenic microorganisms and viruses. The effective solution for reducing the danger is phytoncides plants. For successful phytodesign, an assortment of phytoncides plants of 11 species has been developed: Aspidistra elatior, Aglaonema “Silver queen”, Aglaonema “Maria”, Chlorophytum comosum, Chlorophytum capense, Dracena marginata, Monstera deliciosa, Philodendron scandens, Sansevieria triaeffieria trichelifera, Zamiaculcas zamiifolia. The offered assortment completely corresponds to climatic features of premises. For the normal growth and development of plants in the absence of natural light, three options for additional effective illumination are proposed.
T. Tkachenko and V. Mileikovskyi
For the first time, methodological approaches have been developed and given to determine heat exchange processes in the living vegetation layers of green roofs using total thermal resistance, which takes into account the heat exchange processes directly in it and the heat transfer on its free surface. The approaches take into account wind speed. In addition, for the first time, clarification has been made in the understanding of the term “cooling effect”, as the difference of the temperatures between the living plant layer and the air. The method of its determination is proposed. Engineering approach to thermotechnical calculation of the green roofs is given taking into account the “cooling effect”. Influence of the wind speed on the “cooling effect” has been determined. Based on the influence, the recommendations for parapet construction are provided for “cooling effect control” maximizing energy efficiency of buildings.
Tetiana Tkachenko, Viktor Mileikovskyi, and Adam Ujma
Walter de Gruyter GmbH
Abstract Currently, a very big problem of cities in Europe and the world is air pollution with combustion products of car fuels, generation of heat and electricity. These impurities affect the microclimate of cities significantly. Pollution not only affects the area outside buildings, but getting into their interior through ventilation systems, which has an adverse effect on the indoor environment of buildings. High concentrations of CO 2, cause a weakening of concentration in working people, which affects the deterioration of safety and work efficiency. For assessing air quality improvement on “green roofs”, a field study of CO 2 content has been carried out on the “green roof” of a four-storey building, on a completely identical non-greened building, and on a highway with high-density traffic near them in Kiev. It was found that greening the roof significantly reduces the CO 2 content from 501 ppm on the road and 452 ppm on the roof without protection to 410-415 ppm. It improves the conditions in which people work and rest.