Number Of Solid Particles Research Articles

Reducing real driving fuel consumption and emissions with a hydraulic hybrid vehicle

We have successfully prototyped and tested the real-driving performance of a hydraulic hybrid heavy commercial vehicle. Hydraulic hybrid driveline technology was fitted to a Euro IV diesel truck equipped with a diesel particulate diffuser/filter and an exhaust gas recirculation system. An AVL portable emissions measurement system was fitted to the test vehicle to quantify gaseous and particle phase emissions species and an on-board diagnostic scan tool was used to obtain data from the trucks electronic control unit. Fuel consumption savings up to 17 % were accomplished in hydraulic hybrid mode when testing on a short urban driving route featuring a high intensity of stop-start activity. Average reductions in solid particle number concentration of 40 % were achieved along with increases in NOx, Hydrocarbons (THCs) and CO. Future work could target improved control system integration of the various driveline components to further reduce fuel consumption and emissions in an improved prototype design.

The Influence of Exogenous Particles on Saliva Rheology

This study aimed to investigate the effect of exogenous nanoparticles on the rheological properties of artificial saliva. There are four reasons for undertaking this type of research: Firstly, the number of solid particles of various origins present in the air is still high. Secondly, nanoparticles (including silver and gold nanoparticles) are increasingly used in food packaging and can migrate into food. Thirdly, saliva is the first biological fluid that comes into contact with exogenous particles. Finally, the function of saliva is also closely related to its rheological properties. Due to the remarkable properties of nano-objects, nanoparticles of various origins in the body may cause effects that have not been realised until now. Therefore, each type of nanoparticle must be tested in terms of its impact on the body/body fluid. We used silver and gold nanoparticles because they are used in the food industry, and diesel exhaust particles because they are standard components of air pollution. The effect of various nanoparticles (e.g., their size and shape) on the rheology of saliva at two temperatures was investigated. The constants of the power law constitutive equation were also estimated. Studies showing the impact of nanoparticles on the rheology of body fluids are rare because it is one of the less obvious ways of their affecting the human body. However, the results show that nanoparticles are not neutral to the biological fluid, which may translate into a change in its properties and thus disturb its functions.

PEMODELAN KUALITAS AIR TANAH OLEH AIR LIMBAH DOMESTIK MENGGUNAKAN ARCGIS DI DESA KERTALANGU

<p><em>The community living in Kesiman Kertalangu Village, East Denpasar, Denpasar City, Bali, has a few open shallow wells at home. Well water is used for daily activities such as washing, washing vehicles, and watering plants. The main source of water is groundwater, which is found in rocks below the earth's surface. The availability and movement of groundwater depends on the geological conditions of the area.</em><em> </em><em>Groundwater that is used as a source of community life must meet good water quality, so the purpose of this study was to determine the condition of groundwater during the study. The samples used for groundwater testing were 30 wells spread across this village. The methods used were interviews with the local community, field testing of well water samples (smell and temperature tests), laboratory tests (pH, TSS, TDS, DHL and microbiology) and modeling analysis of all research data results using the ARCGIS application. The research results obtained were field tests such as odor tests and temperature tests that passed the clean water requirements because they met the standards set by the Ministry of Health. laboratory tests such as the TDS, TSS and DHL tests have met the requirements as clean water because the number of solid particles dissolved in water and gas is below the specified limits, and the amount of suspended solids in water is also below the limits. Microbiological test results showed that several points were quite polluted by E.Coli and Total Coliform bacteria caused by the distance between the well points and the septic tank in people's homes.</em></p>

Solid Particle Number (SPN) Portable Emission Measurement Systems (PEMS) for Heavy-Duty Applications

A heavy-duty engine is homologated in a test cell. However, starting with Euro VI regulation, the in-service conformity is controlled with the engine installed in the vehicle using portable emission measurement systems (PEMS). In Europe, the application of solid particle number (SPN) PEMS started in 2021 for compression ignition (diesel) vehicles and in 2023 for positive ignition vehicles, thus including those operating with compressed natural gas (CNG). Even though today only particles with sizes > 23 nm are regulated, the Euro 7 proposal includes particles > 10 nm. There are not many studies on the accuracy of the SPN PEMS, especially for heavy-duty applications. In this study, PEMS measuring > 23 and >10 nm from two instrument manufacturers were compared with laboratory-grade instruments. The particle detector of one PEMS was a condensation particle counter (CPC), and of the other a the diffusion charger (DC). The results showed the robustness and good accuracy (40% or 1 × 1011 #/kWh) of the PEMS for ambient temperatures from −7 °C to 35 °C, active regeneration events, different fuels (Diesel B7, HVO, and CNG), different test cycles, cold start or hot engine operations, and high exhaust gas humidity content. Nevertheless, for the DC-based PEMS, sensitivity to pre-charged urea particles was identified, and for the CPC-based PEMS, sensitivity to pressure changes with one vehicle was nnoticed. Nevertheless, the results of this study confirm that the PEMS are accurate enough to measure even the stricter Euro 7 limits.

Diesel Particle Filter Requirements for Euro 7 Technology Continuously Regenerating Heavy-Duty Applications

The upcoming Euro 7 regulation for Heavy-Duty (HD) vehicles is calling for a further tightening of the Solid Particle Number (SPN) emissions by means of both lowering the applicable limits and shifting the lowest detectable size from 23 nm (SPN23) to 10 nm (SPN10). A late-technology diesel HD truck was tested on a chassis dynamometer in order to assess the necessary particle filtration requirements for a continuously regenerating system. The study showed that passive regeneration under real-world operating conditions can lead to a significant release of SPN10 particles from the current technology Diesel Particulate Filter (DPF) when soot-loaded, even exceeding the currently applicable emission limits. The actual emissions during passive regeneration and following the clean-up of the DPF exceeded the proposed Euro 7 limits by more than an order of magnitude. A prototype DPF, exhibiting a 99% filtration efficiency when clean, was shown to effectively control SPN10 emissions under both operating conditions. The shift to SPN10 also necessitates control of nanoparticles forming inside the Selective Catalytic Reduction (SCR) system, which for the tested truck exceeded the proposed (hot) limit by up to 56%. A dedicated particle filter specifically designed to capture these particles was also evaluated, showing a better than 60% efficiency. The key message of this study is that SPN emissions can be kept at low levels under all conditions.

Scaling Equations for Annular Flow of Yield-Power Law Fluid and Drill Cuttings

Summary Estimation of frictional pressure loss along the wellbore annulus is the key to determining the wellbore equivalent circulating density. Flow loop experiments are commonly used at smaller scales of flow to measure this quantity. However, a complete set of scaling equations between the measured pressure drop gradient along the annulus of a flow loop device and the one occurring in the wellbore is not reported in the literature. This study applies dimensional analysis to make such a connection while accounting for drillpipe rotation and eccentricity, as well as solid cuttings load, in the annular flow of yield-power law drilling fluids. Simultaneous application of geometric, kinematic, dynamic, and rheological similarities allows for developing direct relations between the quantities that govern the laboratory and wellbore scales of flow. For this purpose, a set of dimensionless groups is identified and held equal between the two flow scales. Dimensional analysis shows that scaling the two-phase flow of drilling fluid and drill cuttings entails 10 dimensionless groups. The solution of the obtained scaling equations determines the required volumetric rates of fluid and solid particles, the inner pipe rotation speed, and the fluid rheology in the flow loop device to establish a complete similitude with the wellbore annular flow. The required similarity between the Reynolds numbers of solid particles or drill cuttings at the two scales of flow introduces a constraint on the rheology of the fluid to be used in the laboratory flow loop. This finding indicates that attaining a complete similitude requires the two fluids to be dissimilar. Once all scaling requirements of the considered similitude are applied, the pressure gradient along the wellbore annulus can be obtained directly in terms of the measured pressure drop in the laboratory flow loop.

Tessellated granular metamaterials with tunable elastic moduli

Most granular packings possess shear moduli (G) that increase with the applied external pressure, and bulk moduli (B) that increase or remain constant with pressure. This paper presents “tessellated” granular metamaterials for which both G and the ratio G/B decrease with increasing pressure. The granular metamaterials are made from flexible tessellations forming a ring of closed cells, each containing a small number of solid particles. For under-constrained tessellations, the dominant contributions to G and B are the particle–particle and particle–cell interactions. With specific particle configurations in the cells, we limit the number of possible particle rearrangements to achieve decreasing G as we increase the pressure difference between the inside and outside of the tessellation, leading to G/B≪1 at large pressures. We further study tessellated granular metamaterials with cells containing a single particle and many particles to determine the variables that control the mechanical response of particle-filled tessellations as a function of pressure.

EFFECTS OF HOMOGENEOUS AND HETEROGENEOUS REACTIONS ON THE THERMALLY STRATIFIED WATER-BASED NANOFLUID STREAMING ABOVE AN EXTENDING SURFACE

The effect of homogeneous and heterogeneous reactions, as well as second-order velocity slip, on the magnetic influenced flow of nanofluid (Cu-water and MgO-water) passes above an extending surface has been examined. To alter the nature of leading equations of this problem, a new set of dimensionless variables have been employed. The resulting equations with the corresponding surface restrictions are solved using the Runge-Kutta-Fehlberg technique (RKF45) by developing a code in Maple-18. The outcomes of this investigation are presented in terms of pictorial mode with the effects of different novel flow parameters. Also, numerical values of physical quantities that are associated with this problem are set in terms of tabular mode. It is perceived that increasing the number of solid particles, the thermal and mass fractions of the nanofluid behave as an enhancing function, whereas the motion of the nanofluid is a decreasing function.

Expanding the ethanol blend wall in California: Emissions comparison between E10 and E15

This study assessed the potential of increasing ethanol content in California reformulated gasoline (CaRFG) by investigating the exhaust emissions from a fleet of 20 light-duty vehicles. A baseline CaRFG E10 (10% ethanol by volume) fuel was splash blended with denatured ethanol to create a E15 fuel. Each vehicle/fuel combination were exercised over triplicate Federal Test Procedure (FTP) cycles on a chassis dynamometer. Our results showed no statistically significant fuel effect on nitrogen oxide (NOx) emissions for E15, whereas total hydrocarbons (THC), non-methane hydrocarbons (NMHC), and carbon monoxide (CO) showed either marginally or statistically significant reductions for E15. Particulate matter (PM) and solid particle number emissions were positively impacted by ethanol, exhibiting statistically significant reductions. Acetaldehyde and ethanol emissions responded strongly with ethanol across the fleet of 20 vehicles, while formaldehyde emissions did not show a statistically significant effect. Monoaromatic species and 1,3-butadiene showed mixed results, with ethylbenzene and the xylene isomers showing strong fuel differences. Although no strong differences were found for carbon dioxide (CO2) emissions, E15 showed life cycle greenhouse gas (GHG) emissions savings when compared to E10.

Comprehensive Experimental Design for Evaluating the Effect of Solid Particles on Scaling and Scale Inhibition

This experiment was designed to further develop the innovative and practical skills of undergraduate students. A comprehensive professional experiment was designed to evaluate the effect of particulate matter present in oilfield water for scale inhibitor effect based on the traditional scale inhibitor evaluation method by combining the actual application conditions. This experiment was designed to evaluate the effect of the presence of particulate matter in oilfield water on the effectiveness of scale inhibitors and to improve student’s professional skills. In order to solve the problem that the effect of scale inhibitor will be affected by the presence of a large number of insoluble solid particles in oilfield water, this experiment evaluated the applicability of scale inhibitor in actual oilfield water under different particulate matter and different concentration of experimental conditions. The experiments shows that the presence of solid particles in oilfield water will accelerate the growth rate of calcium carbonate crystals, which will accelerate the generation of calcium carbonate scale crystals and make scale inhibitors less effective. The comprehensive professional experiment was designed in this paper evaluated the effect of particulate matter on scale inhibitor effectiveness under simulated conditions in actual oilfield water, expanding the application of traditional scale inhibitor evaluation methods and improving the professional skills and adaptability of undergraduate students to oilfield conditions.

Off-Cycle Emissions of Particle Number from Gasoline and DPF Diesel Passenger Cars in High-Load Conditions

To evaluate regulated gases and solid particle number (SPN) emissions in high-load off-cycle conditions, two diesel vehicles with a diesel particulate filter (DPF) and a urea selective catalytic reduction (SCR) system, respectively, and four gasoline port fuel injection (PFI) vehicles were tested with the worldwide light-duty test cycle, including an extra-high (Ex-hi) phase. All the tested vehicles were developed for the Japanese market and did not comply with the Ex-hi phase. All vehicles exhibited higher CO2 emissions in the Ex-hi phase than in low, the mid and high phases. Increased NOx and SPN10-23 emissions were observed with the DPF vehicle. These increased emissions were due to the occurrence of passive regeneration of the DPF, and the urea SCR system was stopped as a result. The small gasoline PFI cars showed increased CO and SPN emissions in the Ex-hi phase. These emissions were due to enrichment control, which occurred in a quite high load operation condition. The feature of higher emissions with enrichment control differed from that observed in a warming-up process in the cold-start mode. SPN23 increased mainly in the warming-up process, whereas SPN10-23 increased in the Ex-hi phase with enrichment control. Hybrid vehicles seem to have fewer opportunities to show the enrichment control due to motor assist.

Laboratory measurements with solid particle number instruments designed for periodic technical inspection (PTI) of vehicles

Particulates emitted by vehicles can be significantly reduced with the use of particulate filters. In some European countries, the control of these filters’ efficiency during their lifetime is done with a recently introduced solid particle number (SPN) test at low idling performed during periodic technical inspection (PTI) of Diesel vehicles. This paper examines the counting efficiency, linearity, and volatile removal efficiency of seven SPN-PTI instruments with laboratory-based particle generators and with vehicle exhaust. Some challenges related to low monodisperse particles concentration were identified during counting efficiency tests and discussed in view of type examination procedures. In agreement with the current metrological requirements, the maximum error (i.e., deviation from reference) of all instruments at linearity checks was < 25 % in a wide range of concentrations when testing with carbonaceous particles but error levels depended on the particle material used for testing. Finally, tetracontane removal efficiency of all instruments was > 95 %.

Cavitation erosion and corrosion resistance of hydrophobic sol-gel coatings on aluminium alloy

Cavitation erosion and erosion-corrosion are the popular failure modes of hydronautics components namely propellers, valves, turbines etc which occurs due to mechanical destructions and electrochemical corrosion. Erosion corrosion is caused due to surge in the number of solid particles affecting the surfaces whereas cavitation erosion is caused due to steady collapse of cavities or bubbles. Aluminium alloys are widely used in marine renewable industries owing to its high strength, light weight and good corrosion resistance. Despite that, cavitation and erosion-corrosion are the limiting factors for these alloys. The aim of the present work is to produce a coating system capable of replacing chromate-conversion coatings on aluminium alloy by combining an anodised layer with additional deposition of superhydrophobic sol-gel coatings. Fundamental characteristics that affect the coating's corrosion and cavitation erosion namely adhesion and thickness was evaluated. Hardness and elastic modulus of the coatings was evaluated using a Nanoscratch mechanical tester. Electrochemical behaviour of the coatings was assessed using Potentiodynamic scanning (PDS) and electrochemical impedance spectroscopy (EIS). Prolonged performance was studied using neutral salt spray test (NSS). Cavitation erosion resistance of the coatings was investigated in laboratory using a standard ultrasonic test apparatus according to ASTM G32-16. Erosion rate of the coatings was evaluated based on cumulative mass loss v/s testing time. SEM/EDX was used to evaluate the surface damage caused by erosion-corrosion and cavitation erosion. The analysis was done aiming to decide if the developed coatings was a better alternative to protect the metals from corrosion and cavitation erosion.

Interactions between solid–fluid particles during thermosolutal convection of a rotating cylinder in a cavity

The ISPH method is adopted to simulate the diffusion of solid particles through a nanofluid flow during the dual rotation of two circular cylinders inside a cavity. Half of the solid particles are carrying and the others carry . The novelty of this work is in simulating the dual rotation of circular cylinders with the dispersion of solid particles below the influences of Soret-Dufour numbers. The major outcomes revealed that the interactions between solid particles and nanofluid flow are enhanced according to an increase in Soret/Dufour numbers. Increasing the Hartmann number declines the interaction process between solid particles and nanofluid flow. The radius of a circular cylinder is working well in changing the transport of heat/mass within a cavity due to the variations in the total number of solid particles. The values of Nusselt and Sherwood numbers are influenced by physical factors.

Influence of the In-Cylinder Catalyst on the Aftertreatment Efficiency of a Diesel Engine

The article discusses the use of a catalyst inside the cylinder, the task of which is to reduce exhaust emissions from a diesel engine. The catalyst (platinum) applied to the glow plugs provided an additional method of exhaust aftertreatment. Due to their usage, especially in urban driving, passenger cars are characterized by small mileage between individual trips, so they often operate from a cold engine start and work at a low engine temperature, which leads to reduced catalytic reactor efficiency. For this reason, the efficiency of the internal catalyst was tested in relation to the efficiency of the external reactor. This efficiency was determined based on exhaust emission measurements (before and after the catalytic reactor) in two stages: stage 1: idling of a hot engine, and stage 2: simulation of the NEDC test (valid for the selected test object). The tests were carried out on an engine dynamometer, where the traffic conditions from the type-approval test carried out on a chassis dynamometer could be replicated. The tests were carried out on a Euro 4 1.3 JTD MultiJet diesel engine. The results (measurement of carbon monoxide, hydrocarbons, and the number of particles) related to the assessment of the effect the catalyst in the cylinder were discussed. The obtained catalytic reactor efficiency results, regardless of the type of research, indicated that it achieved the highest efficiency in reducing the concentration of hydrocarbons, and the lowest—in relation to the number of solid particles (as that is not its primary function). It is particularly significant that the in-cylinder catalytic converter was most efficient during the cold engine start, which happens frequently in urban driving. The efficiency of the diesel oxidation catalytic reactor (DOC) during the engine start-up and warm-up phases with the use of standard glow plugs reached values of 31.3%, 34.1% and 14.3%, respectively, for carbon monoxide, hydrocarbons and the particle number. On the other hand, the determined efficiency of the DOC in a setup with the modified glow plugs was 28.9%, 35.7% and 12.5%, respectively. The proposed solution can be used to improve the combustion quality in internal combustion engines used in hybrid vehicles, which are characterized by frequent engine starts and stops. In addition, it is possible to use such a solution retroactively in traditional vehicles powered by an internal combustion engine, which could result in an improvement in their emission class through what is called retrofitting.

On the Importance of Model Selection for CFD Analysis of High Temperature Gas-Solid Reactive Flow; Case Study: Post Combustion Chamber of HIsarna Off-Gas System

In this paper a CFD analysis of HIsarna off-gas system for post combustion of CO-H2-carbon particle mixture is presented to evaluate the effect of different sub-models and parameters on the accuracy of predictions and simulation time. The effects of different mesh type, mesh grid size, radiation models, turbulent models, kinetic mechanism, turbulence chemistry interaction models, including and excluding gas-solid reactions, number of reactive solid particles are investigated in detail. Based on the accuracy of the predictions and agreement with counterpart measured values, the best combination is selected and conclusions are derived. It was found that radiation and turbulence chemistry interaction model have a major effect on the temperature and composition profile prediction along the studied off-gas system, compared to the variations in other models. The effect of these two models becomes even more evident when the temperature and fuel content of the flue gas are high.

Characterization of Soot Loading and Filtration Efficiency of a Gasoline Particulate Filter with Photoacoustic Sensor and Particle Number Counting Systems

An optimum operation of a gasoline particulate filter (GPF) for a gasoline direct injection vehicle in terms of its performance of pressure drop, soot loading, and filtration efficiency becomes inevitable to fulfill upcoming emission regulations. This paper proposes a methodology to characterize the GPF performance for validation of simulation models for more precise operation strategies along with future legislative requirements. The feasibility was examined through experiments of miniature GPF samples using a synthetic particle generator. Firstly, permeability of the GPF walls was estimated to be 6.9 ± 1.5 × 10−13 m2 by a flow resistance descriptor model, which was in good agreement with its pore structure. Secondly, photoacoustic sensor systems indicated soot accumulation inside the GPFs in real time thanks to linear correlations between sensor signals and soot mass concentrations in exhaust. Thirdly, particle number counting systems compliant with respective regulatory technical requirements exhibited time-resolved filtration efficiencies of the GPFs in conjunction with solid particle number emissions whose diameter was larger than 10 nm and 23 nm. The filtration efficiencies at a clean state of the GPF were 0.78 and 0.77, respectively. The slight difference could be explained by Brownian diffusion and interception for particle filtration.

Interlaboratory Study on Brake Particle Emissions Part II: Particle Number Emissions

The Particle Measurement Programme (PMP) informal working group co-ordinated a global interlaboratory study (ILS) on brake wear particle emissions with the participation of 16 laboratories in 2021. Two articles present the results of the ILS: (I) particulate matter mass (PM) and (II) particle number (PN) emissions. The test matrix covered different brake systems, including ECE and NAO pad materials with grey cast iron discs and a drum brake. Regarding PN, the study measured the total particle number from approximately 10 nm to 2.5 µm (TPN). Some testing facilities measured solid particle number emissions (SPN) in parallel. The mean TPN concentrations ranged from 9.1 × 108 #/km/brake to 1.1 × 1010 #/km/brake. TPN and SPN emission levels were comparable, except for one lab that measured very high volatile particle emissions for one brake system. The minimum and maximum SPN emissions for a given brake differed by a factor of 2.5 ± 0.5, comparable to data from exhaust SPN ILS measurements. This article provides an overview of lessons learned and subsequent measures incorporated in an upcoming global technical regulation to reduce measurement variability when sampling and measuring brake particle emissions for light-duty vehicles up to 3.5 t.

Structural optimization and separation characteristic of a separating device for three phases: Oil, water and solid

Solid particles and water are widely used as lubricating oils. However, oil–water–solid separation is inefficient when conventional methods are used. Therefore, a device is proposed to simultaneously separate oil, water, and solids from one another. In this study, a numerical model was established by combining the mixture, Reynolds stress, population balance, and discrete-phase models to investigate the separation characteristics of a separating device. The effect of the structural parameters on the separation was investigated, and the important structural parameters were optimized using the response surface method. The results indicate that the optimal underflow pipe, certain pipe, and sideflow pipe diameters are 6.5, 13.49, and 7 mm, respectively; at this instant, the tangential velocity in the small cone section and certain structure is large, the oil volume fraction is low near the underflow pipe, and the number of solid particles separating from the sideflow outlet increases, and the deoiling rate and desolidification rate reach a maximum of 84.45% and 91.44%. This study can provide valuable guidance for the design of high-performance devices for lubricating oil purification using physical methods.

Euro VI-d Compliant Diesel Engine's Sub-23 nm Particle Emission.

Passenger and commercial transportation significantly contribute to hazardous air pollution. Exhaust gas after-treatment technology advances closely to the emission regulations throughout the world. The upcoming legislation will be EURO VII in European Union, which requirements are not set yet, but the Solid Particle Number (SPN) diameter range is expected to be more severe compared to EURO VI. This paper will revisit the measurement principle differences between over 10 nm and over 23 nm diameter particles in theory and practical engine bench measurement. Two different types of particle counters have performed the soot particle counting measurement; therefore, the applied sensors are different in terms of applied counting principles. The measurement principles of both devices will be introduced, and the experiment's result will reflect on the sensor differences. From this, a conclusion can be derived in order to determine the severity of the upcoming EURO VII legislation in terms of SPN, and the experiment will also reflect on the measurement sensor differences. The overall results suggested that extending the lower range of the measurement increases the tailpipe particle emission by 20%, although the DPF filtration efficiency is still over 99%.