Engine Oil Research Articles

Bioenergy recovery from waste engine oil through anaerobic co-digestion with sewage sludge: Effects of total solids and inoculum to substrate ratio

ABSTRACT Considering their various benefits, such as pollution control, waste management, and eco-friendly energy production, much more attention is currently devoted to utilization of some urban, industrial, and agricultural wastes in the course of anaerobic digestion (AD) across the world. From this perspective, the present study aimed to evaluate prospects of biogas production from waste engine oil (WEO) through its co-digestion (CoD) with activated municipal sewage sludge (SS). In order to do this, AD was carried out in batch-mode 1-L reactors at a mesophilic temperature of 35°C, with consideration for total solids (TS) levels of 3% and 6% and inoculum-to-substrate ratios (ISRs = 0.5, 1, and 2), which were based on volatile solids (VS), over a period of 85 days. The treatment with TS = 6% and ISR = 2, or 6874 mL, showed the maximum biogas generation rate, according to the trials, with TS and VS removal values of 23% and 28%, respectively. As well, reactor monitoring during AD revealed that the parameters of potential of hydrogen (pH) and alkalinity recovered following acidification after 7 days, and the relatively low efficiency of the given process (0.233 m3/kg-VSadded) was attributed to the highly complicated and difficult-to-degrade structure of WEO. The kinetics of anaerobic CoD consistently established that the maximum cumulative biogas production rate (Rm = 5.61 m3/kg-VSadded.d) and the shortest biogas production lag time (λ = 0) occurred when there were TS = 3% and 6%, in that order. Moreover, kinetic models, i.e. the Modified Gompertz and Logistic Function ones, were found to be in very good agreement with experimental data, whereas the first-order model failed to offer ideal predictions of biogas production trend in most cases.

Study concerning methods for managing used engine oil. Analysis of a questionnaire-based survey

Abstract This paper focuses on methods of managing used engine oil by presenting an analysis of the results of a survey based on a questionnaire designed by the authors, which aims to illustrate the real, objective situation of the management of used engine oil generated by vehicles powered by internal combustion engines. The answers are analyzed for each question separately and both conclusions and implementable objectives that could improve the current situation are highlighted. In order to facilitate the understanding of the current framework, general aspects regarding the management of used engine oil are also presented, with an emphasis on the legislative perspective.

Diagnosing the truck engine operation by evaluating engine oil wear and issuing maintenance recommendations

Abstract The lubricating oil of an internal combustion engine (i.c.e.) performs several functions having a major contribution to the reliability of the system, implying proper operation during the period of exploitation. Replacing the engine oil ahead reaching the turnover / time corresponding to preventive maintenance it turns out to be sometime an imperative action, with negative implications on operating costs. Any user of today vehicles desire to use the engine performances at full percentage, and for that an important condition becomes the changing of the oil at defined intervals of time/rollover intervals. Thus, it is very important to be aware when to replace because a late change of oil can affect the engine operation and, surely, the performance of the vehicle. Premature oil change influences costs, the environment and is considered a harmful action in terms of the process of depletion of resources. As regards the operating conditions, it is intended that they are similar for all vehicles taken into consideration. It is imperative that the study be carried out by investigating the operation of a single type of engine, with a single type of engine oil, for several vehicles with the same technical characteristics. It is considered that the transport fleets are the concrete source that falls under the already mentioned conditions and a methodology based on the analysis of the 10W30 oil samples used in the MX - 11 330 H2, EURO 6 engines of the DAF vehicles within the fleet of one transport company from Argeş county will be used. The authors of this paper will analyze the following properties of the oil: viscosity, density, flash point, contamination with fuel and water content, these being the most important in illustrating the degree of wear and tear of it. The information about the evolution during the exploitation period of these characteristics is the basis for the elaboration of maintenance strategies considering the three desiderata: the environmental issues, the vehicle’s reliability, and the operating costs of the vehicle.

Evaluating Household Hazardous Waste Generation, Composition, and Health Risks in an Urban Municipality

This study aimed to assess the generation rate and composition of household hazardous waste (HHW) in Nakhon Si Thammarat Municipality, Thailand. A questionnaire survey was conducted to collect data on HHW generation and disposal practices from households in the municipality. Soil samples were collected and analyzed for heavy metals (cadmium, chromium, mercury, nickel, and lead) and PCBs contamination. The potential health risks from ingestion exposure associated with heavy metals and polychlorinated biphenyls (PCBs) contamination in the soil were evaluated. The result revealed that in 2023, the HHW generation rate was 11.95 kg/household/year, with the highest percentages occurring of electronic waste (17.40%), fluorescent lamps (16.98%), spray cans (12.38%), cleaning products (11.30%), and engine oil and lubricant oil products (9.87%). The majority of residents (92.90%) disposed of hazardous waste and general waste together in public waste containers. However, the health risk assessment indicated that the levels of heavy metals and PCBs in the soil were within the safe acceptable range for residents, with a total lifetime cancer risk from ingestion exposure of less than 1E-06 for both adults and children. The findings highlight the need for improved waste separation practices and the implementation of effective hazardous waste management strategies to minimize potential health risks and environmental impacts. This study serves as a basis for developing targeted interventions and policies to enhance household hazardous waste management in the municipalities and similar urban areas in Thailand. Doi: 10.28991/HEF-2024-05-03-011 Full Text: PDF

Evaluation of Physicochemical Parameters, Total Bacteria Count and some Heavy Metal Levels in Soil from Automobile Workshop Activities at Nnewi Local Government Area, Anambra State, Nigeria

Disposal of used motor oil and chemical substances on land leads to loss in soil quality by minimal abundance and variety of microorganisms in soil. The objective of this paper was to evalaute the physicochemical parameters, total bacteria count and some heavy metal levels in soil from automobile workshop activities at Nnewi Local Government Area, Anambra State, Nigeria. Using field survey and appropriate standard laboratory analyses, the results showed that the control uncontaminated soil samples recorded high bacteria count (6.9 x106 cfu/g). The available soil nitrogen(9.0), soil nutrients nitrate (15.10) and phosphorous (17.3) all recorded appropriate values when compared with WHO standard. The acidity of the soil using pH value as an indicator showed that the uncontaminated control soil samples were acceptable for crops also the Ec values. The heavy metals analysed indicates that the control soil samples were also moderate in heavy metals accumulation when compared with the contaminated soil samples particularly Cd, Pb (0.08) and Hg (0.01) while Cd was not detectable. These findings have shown that automobile activities can denature soil properties which could lead to soil infertility. The automobile activities has to be controled by the concerned agencies in Nigeria. Environmental education should be encouraged to reduce effects of anthropogenic activities on soil quality in the study area.

Controllable Oil Adsorption from water Using Hydrophobic (Paraffin/Stearic Acid)/CoFe2O4 Magnetized Fibril Wax

Abstract The development of efficient oil-water separation techniques is critical for mitigating environmental pollution from industrial oily wastewater. This study synthesized a hydrophobic and oleophilic (paraffin/stearic acid) (Par/St)/CoFe2O4 magnetized fibril wax for controllable adsorption and removal of waste engine oil from water. Structural and morphological characterization confirmed the successful incorporation of 30 wt% CoFe2O4 nanoparticles into the Par/St wax matrix with fibril morphology. Structural and morphological characterization using TEM, UV-Vis, FTIR, XRD, and SEM consistently confirmed the successful integration of CoFe2O4 nanoparticles into the Par/St wax matrix, forming fibrils with a high surface area. The oleophilic fibril demonstrated rapid adsorption and excellent removal efficiency of 99% for waste engine oil within 30 seconds. The fibrils could be magnetically guided for oil collection, ensuring reusable and eco-friendly oil remediation. This work introduces a novel solution for controllable oil spill clean-up and oily wastewater treatment.

The pyrolytic distillation of waste lubricants with waste oilfield scale into value-added fuel

The ever-increasing generation of waste materials has become a major environmental concern, highlighting the need for sustainable waste management strategies. This study explores the catalytic pyrolysis of waste lubricant oils using a waste oilfield scale as a low-cost solid catalyst to produce value-added fuel products. The pyrolytic distillation of waste engine oil was carried out in a manual distillation unit, employing a calcium carbonate (CaCO3) scale as a catalyst under various reaction conditions. Distillation experiments were conducted at 300 °C, 320 °C, and 350 °C, with and without adding NaOH and CaCO3 catalysts. The distillate fractions were characterized, and their properties were compared to standard fuel specifications. The results demonstrated that increasing the pyrolysis temperature and employing CaCO3 as a catalyst significantly enhanced the distillate yield and improved key fuel properties. At 350 °C, the distillate yield reached 56 % with 4 g of CaCO3, exhibiting desirable density (0.8049 g/cm3), viscosity (2.31 cSt at 40 °C), sulfur content (0.43 wt%), and a calorific value of 43,152 kJ/kg. Further, the distillate fractions were separated into gasoline (80–150 °C), kerosene (180–270 °C), and gas oil/diesel (270–350 °C) ranges, with the diesel fraction showing a promising cetane number of 51. The catalytic pyrolysis fuel (CPF) obtained from distillation with 4 g CaCO3 at 350 °C, followed by bleaching with CaO, exhibited excellent properties, including a density of 0.8297 g/cm3, viscosity of 2.71 cSt at 40 °C, pour point of −12 °C, sulfur content of 0.201 wt%, and a calorific value of 43,961 kJ/kg. The GC analysis revealed a paraffin-rich composition in the desired fuel ranges, contributing to the desirable fuel properties.

A comparative study of the lubricating properties of various types of base oils containing hydrogen emulsions

The aim of this study is to evaluate the lubricating performance of various base oils in a hydrogen-enriched environment. Experiments were conducted wherein base oils were emulsified with meticulously calibrated hydrogen concentrations, followed by a series of friction and wear measurements. Elemental analysis was performed on the worn surfaces, providing further insight into the wear mechanism. The findings of this study highlight the pronounced effect of hydrogen on the lubrication of pure water emulsions of Class IV 4 base oils, with the Class V 5-1 base oils showing optimal lubricating performance in hydrogen-enriched conditions. SEM images at high magnification scanning revealed the presence of a protective friction film on the surfaces of the wear scars in each sample. X-ray photoelectron spectroscopy (XPS) identified traces of metal sulfide within the friction film, which may play a role in reducing friction. The formation of this friction film is likely a contributing factor to the enhanced lubricating performance of the base oil. These findings contribute a substantial foundation for the development of standards for evaluating the performance of hydrogen internal combustion engine oils.

Insight into co-pyrolysis of waste polypropylene and engine oil for liquid hydrocarbons and interaction mechanism by kinetic analysis and DFT simulation

Plastic pyrolysis is an efficient and cost-effective way of processing plastic waste, producing oil, gas, and coke. Oil production from waste plastics is a promising technology, and co-pyrolysis of multicomponent materials can help to promote reactions and optimize the products. Therefore, this study examines the co-pyrolysis reaction of another hazardous waste, engine oil, with waste plastics. The co-pyrolysis performance of plastic is first evaluated and the TG-DTG curve is dynamically analyzed. Then the synergistic behavior of polypropylene and engine oil co-pyrolysis is revealed through a combination of experiments, kinetic analysis, and DFT calculations. For physical interactions, waste engine oil can improve heat and mass transfer performance during pyrolysis, significantly increase the heating rate of the reactants. Furthermore, the yield of liquid-phase products is increased. For chemical interactions, the optimal pyrolysis path was studied according to activation energies and the interaction mechanism was elucidated. Moreover, the optimal pyrolysis paths of the engine oil and PP were identical, with the resulting pyrolysis products having minimal difference in carbon chains. However, the detailed reaction paths need to be further explored owing to the complexity of the process. And the detailed composition of the pyrolysis products requires further comprehensive analysis.

Entropy optimization in multigrade motor oil based nanofluid: a spectral and sensitivity analysis with particle shape and dispersion effects

PurposeThis study aims to enhance heat transfer efficiency while minimizing friction factor and entropy generation in the flow of Nickel zinc ferrite (NiZnFe2O4) nanoparticles suspended in multigrade 20W-40 motor oil (as specified by the Society of Automotive Engineers). The investigation focuses on the effects of the melting process, nonspherical particle shapes, thermal dispersion and viscous dissipation on the nanofluid flow.Design/methodology/approachThe fundamental governing equations are transformed into a set of similarity equations using Lie group transformations. The resulting set of equations is numerically solved using the spectral local linearization method. Additionally, sensitivity analysis using response surface methodology (RSM) is conducted to evaluate the influence of key parameters on response function.FindingsHigher dispersion reduces entropy production. Needle-shaped particles significantly enhance heat transfer by 27.65% with melting and reduce entropy generation by 45.32%. Increasing the Darcy number results in a reduction of friction by 16.06%, lower entropy by 31.72% and an increase in heat transfer by 17.26%. The Nusselt number is highly sensitive to thermal dispersion across melting and varying volume fraction parameters.Originality/valueThis study addresses a significant research gap by exploring the combined effects of melting, particle shapes and thermal dispersion on nanofluid flow, which has not been thoroughly investigated before. The focus on practical applications such as fuel cells, material processing, biomedicine and various cooling systems underscores its relevance to sectors such as nuclear reactors, tumor treatments and manufacturing. The incorporation of RSM for friction factor analysis introduces a unique dimension to the research, offering novel insights into optimizing nanofluid performance under diverse conditions.

Rapid analysis of spilled petroleum oils by direct analysis in real time time-of-flight mass spectrometry with hydrophobic paper sample collection

BackgroundOil spills are widespread and can cause devastating environmental consequences. Rapid oil identification is critical to find the origin of the spill, monitor the environment, and lead to informed mitigation measures. The current standard methods in oil spill identification are precise and reliable, but require extensive sample preparation, long instrument runs, and time-consuming data processing. Direct analysis in real time time-of-flight mass spectrometry (DART-ToF MS) has been employed to screen for spilled petroleum oils, with results obtained in mere hours. The present study introduced an innovative, simple, and fast oil sampling method using hydrophobic filter paper and demonstrated its compatibility with DART-ToF MS analysis. Motor oils, jet fuels, marine diesels, crude oils, intermediate fuel oils, heavy fuel oils, and diluted bitumen were collected using the filter paper sampling method. Classification models were constructed from the spectral data by heat map inspection followed by principal component analysis (PCA) and discriminant analysis of principal components (DAPC). Oil slicks and weathered oil slicks were prepared from five oil types, and samples from each slick were collected using filter paper.ResultsThe filter paper technique allowed for effective oil sampling and data acquisition by DART-ToF MS for diluted source oils, oil slicks and weathered oil slicks. Classification via the constructed DAPC models indicated that the DART-ToF MS instrument in tandem with filter paper sampling and multivariate statistics can accurately identify common oil types, with significant improvement of sample collection and turnaround time.ConclusionsThe promising classification results, simple sample collection, and rapid data analysis illustrate the potential use of hydrophobic filter paper and DART-ToF MS as tools in managing large scale oil spill emergency situations.

Modeling and design optimization of the performance of stone matrix asphalt mixtures containing low-density polyethylene and waste engine oil using the response surface methodology

In recent years, the use of waste plastic materials such as low-density polyethylene (LDPE) to modify asphalt binders and enhance mixture performance has garnered significant attention. One major concern with using such materials is the higher production temperature required, which necessitates the use of a bitumen extender agent, such as waste engine oil (WEO), to reduce the viscosity and mixing temperature. Therefore, using these stabilizing additives can reduce the consumption of virgin binder, especially for Stone Matrix Asphalt (SMA) mixtures, which require higher asphalt content. This study aimed to optimize the design of SMA modified by LDPE and WEO to minimize the optimum asphalt content (OAC) and mixing temperature while maximizing SMA performance. To achieve this, Response Surface Methodology (RSM) was utilized to develop the necessary models for optimizing design and predicting performance. The selected independent variables (factors) for the design include LDPE content, WEO content, OAC, and mixing temperature. Meanwhile, the responses (dependent variables) consist of Marshall stability, rut depth, tensile strength ratio, and resilient modulus, which were used to determine the best mix design. The findings demonstrated that the suggested models for the output variables can predict performance with a higher level of confidence. The Analysis of variance (ANOVA) demonstrated that predictive models were significant and well-fitted, with a coefficient of determination (R2) of higher than 0.80, an adequate precision value of greater than 4, and a low p-value (less than 0.05). The error percentage between the RSM-predicted and actual values was less than 5 %, indicating that RSM-established models can accurately and efficiently predict the SMA performance. The best mix design of the SMA mixture modified by LDPE and WEO was found to be 10 % LDPE, 3.91 % WEO, 5.92 % OAC, and mixing temperature of 152.24°C with a combined desirability of 82.8 %.

Chemometric Classification of Motor Oils Using 1H NMR Spectroscopy With Simultaneous Phase and Baseline Optimization

ABSTRACTHere, we demonstrate mid‐field 1H NMR spectroscopy combined with chemometrics to be powerful in the classification and authentication of motor oils (MOs). The 1H NMR data were processed with a new algorithm for simultaneous phase and baseline correction, which, for crowded spectra such as those of the refinery products, allowed for more accurate estimation of phase parameters than other literature approaches tested. A principal component analysis (PCA) model based on the unbinned CH3 fingerprint region (0.6–1.0 ppm) enabled the differentiation of hydrocracked and poly‐α‐olefin‐based MOs and was effective in resolving mixtures of these base stocks with conventional base oils. PCA analysis of the 1.0‐ to 1.14‐ppm region enabled the detection of poly (isobutylene) additive and was useful for differentiating between single‐grade and multigrade MOs. Non‐equidistantly binned 1H NMR data were used to detect the addition of esters and to establish discriminant models for classifying MOs by viscosity grade and by major categories of synthetic, semisynthetic, and mineral oils. The performances of four classifiers (linear discriminant analysis [LDA], quadratic discriminant analysis [QDA], naïve Bayes classifier [NBC], and support vector machine [SVM]) with and without PCA dimensionality reduction were compared. In both tasks, SVM showed the best efficiency, with average error rates of ~2.3% and 8.15% for predicting major MO categories and viscosity grades, respectively. The potential to merge spectra collected from different NMR instruments is discussed for models based on spectral binning. It is also shown that small errors in phase parameters are not detrimental to binning‐based PCA models.

Enhancing the heat transfer in CuO-MWCNT oil hybrid nanofluid flow in a pipe

In this study, three-dimensional steady-state laminar flow simulations were conducted in a horizontal pipe using CuO and multi-walled carbon nanotubes (MWCNT) nanoparticles with engine oil as the base fluid. Various nanoparticle volume fractions were examined under a constant heat flux boundary condition applied to the pipe wall. The main goal was to assess and compare the effects of different nanoparticle volume concentrations, including CuO and MWCNT in ratios of 1:1 and 1:2, on convective heat transfer. A second-order discretisation method was employed for solving the equations, and the SIMPLE algorithm was used for pressure–velocity coupling in the CFD code. The study focused on the impact of nanoparticle volume fraction on the convective heat transfer coefficient and the Nusselt number at a Reynolds number of 750. The findings indicate that increasing the nanoparticle volume fraction enhances both the convective heat transfer coefficient and the Nusselt number, with MWCNT having a more pronounced effect compared to CuO. Specifically, adding 2% CuO increases the heat transfer coefficient by 65%, while a mixture of 1% CuO and 1% MWCNT boosts it by 75%. The thermal boundary layer thickness also grows with higher nanoparticle concentrations, with 1% CuO and 3% CuO increasing the thickness by 1.5% and 3.6%, respectively. A formula for the thermal boundary layer thickness in CuO-oil nanofluids is provided based on volume fraction, and a scale analysis of the average heat transfer coefficient confirms that the simulation results are consistent with this analysis.

Tribological properties of diamond-like carbon films lubricated with water-emulsified engine oil

In this work, the tribological properties of two diamond-like carbon (DLC) films were investigated at different temperatures using water-engine oil emulsions as lubricants, considering emerging fuel systems such as hydrogen and ammonia. The results revealed that the friction coefficient of a-C film raised with the increasing water content at 80 °C. The friction coefficient of a-C:H film initially raised and then decreased with varying water fractions at different temperatures. Elevated temperature exacerbated the wear of both DLC films at high water contents. The most significant wear was observed for a-C film at 80 °C and a-C:H film at 50 °C. The a-C:H film exhibited more sensitive wear characteristics to water content than the a-C film. Surface analysis indicated that water-engine oil emulsions prevented the formation of phosphate tribo-film on steel friction pair for two DLC films but promoted the tribo-oxidation of steel pair sliding contact with a-C film, especially at higher temperatures. Distinct reactivities of two DLC films towards water molecules could affect the adsorption of lubricants on DLC surfaces, leading to their different friction and wear behavior. It suggests that the water-caused emulsification of lubricating oil will be a pivotal consideration in tribological applications of DLC films in future internal combustion engines.

Contribution to the analysis of the physico-chemical and rheological degradation of 15w40 lubricating oils for the optimization of drain intervals

Degradation of engine oil can lead to a reduction in its effectiveness in reducing friction, which has a negative impact on engine durability and performance. This research examined in detail the physico-chemical and rheological properties of new and used motor oils, divided into three groups (A, B and C) and subjected to different driving distances (0 km, 4000 km and 7000 km). The main findings include: Progressive degradation of kinematic viscosity at 40°C with increasing distance travelled, with greater degradation in group A. A similar degradation in kinematic viscosity at 100°C, with Group A showing the greatest degradation, suggesting a loss of efficiency at higher temperatures. A progressive decrease in viscosity index with increasing distance travelled. Significant changes in the total acid number (TAN) and total base number (TBN) of the oil with increasing distance travelled, with the greatest decrease in TBN observed in group C, suggesting acidification of the used oil. A progressive decrease in the sulfur content of used oil compared to new oil, mainly in group C. A progressive deterioration in dynamic viscosity with increasing distance travelled, particularly at higher temperatures. These results highlight the importance of regular maintenance and servicing of thermal engine lubricating oils particularly in an urban driving. future work Develop a predictive model using neural networks to analyze physical, chemical, and rheological properties, and monitor it online.

Zn-doped bentonite catalysts for waste engine oil cracking: Thermal treatment offers a cleaner alternative to acid activation

This study investigates the cracking of waste engine oil (WEO) using bentonite clay (BC) activated through acid and thermal methods, as well as with Zn-doped BCs. Acid activation with 1 M HCl and Zn doping did not alter the BC catalyst’s structure. XRD and SAED analyses confirmed the crystallinity, while TEM showed partial destruction of the layered structure. XRF analysis indicated reduced Al and Si content upon Zn-doping due to high cation exchange capacity. Zn-doping decreased surface area and pore volume but increased acidic sites in acid-treated catalysts, although Zn suppressed these sites in calcined BC. Zn-doped catalysts displayed higher thermal stability. Cracking WEO at 450 °C for 45 min, with and without catalysts, yielded high liquid product recovery (72.6 %–82.8 %), primarily carboxylic acids and aromatics. This demonstrates the potential of Zn-doped BC as an effective catalyst for converting WEO into valuable products, aiding waste management and resource utilization.

Introduction, Types, Properties, and Applications of Switchable Solvents: A Review

AbstractSwitchable solvents (SS) are a class of liquids with the unique ability to significantly alter their physical properties in response to external stimuli such as changes in temperature or the introduction or removal of CO2 gas. This reversible behaviour allows them to return to their original state with minimal changes, making them highly advantageous for various applications. A notable example of a switchable solvent is waste carbon dioxide gas, which is non‐toxic, non‐flammable, and cost‐effective. The versatility of switchable solvents extends to their polarity and physical states, which can be modified through molecular adjustments, opening new pathways for research and industrial applications. This review provides a comprehensive overview of switchable solvents, including their classification, history, properties, and applications, with a particular focus on their role in green chemistry. The types of switchable solvents discussed include Switchable‐Polarity Solvents (SPS), Switchable‐Hydrophilicity Solvents (SHS), and Switchable Water. Each type is examined in terms of synthesis, chemical properties, and development. The desirable properties of switchable solvents, such as their efficiency and recyclability, make them suitable alternatives to traditional solvents in various fields. Their applications range from water treatment and oil extraction to cleaning solid particles and recovering residual motor oil. Additionally, switchable solvents have proven effective as reaction media and in recovering polystyrene from foam. This paper also highlights the environmental benefits of switchable solvents, emphasizing their role in reducing the ecological impact of chemical processes. The potential for future developments in this field is significant, with ongoing research aimed at enhancing their performance and expanding their applications. By providing a detailed analysis of switchable solvents, this review aims to support researchers and industry professionals in developing more sustainable and efficient chemical processes.

محاكاة تدفق السوائل النانوية الصفائحية على خطوة ساخنة مزدوجة مواجهة للخلف

This research focuses on heat transfer enhancement by separating flow over a double backward-facing step using nanofluid. To conduct this research, a numerical model was constructed using the ANSYS Workbench, and the governing equations were solved using the realizable k-ε model with a second-order upwind scheme. Three different types of base fluid (water, engine oil, and ethylene glycol) with nanoparticles (AL2O3, TiO2, and Cu) were used for Reynolds numbers ranging from 200 to 1000. The constant heat flux of the 2000 W/m2 boundary condition is considered on the lower wall. The effect of nanoparticle material, nanoparticle concentrations, nanoparticle sizes, and Reynolds numbers on the Nusselt number is investigated. Two different approaches for estimating nanofluid thermal conductivity and viscosity have been used. The numerical code results were verified with previous numerical data. The results showed that the peak of the Nusselt number occurs immediately after the steps. The results demonstrated a significant improvement in the heat transfer performance of nanofluids, especially Cu/engine oil nanofluids, compared to conventional base fluids with other nanoparticles. It was noticed that the Nusselt number increases with decreasing nanoparticle diameter and also with increasing Reynolds number.

Impact of activation energy and thermal radiation on hybrid nanofluid (engine oil + nickel zinc ferrite + manganese zinc ferrite) flow over a wavy cylinder in the presence of induced magnetic field

Impact of activation energy and thermal radiation on hybrid nanofluid (engine oil + nickel zinc ferrite + manganese zinc ferrite) flow over a wavy cylinder in the presence of induced magnetic field