Medium Flow Rate Research Articles

Performance assessment of annular thermoelectric generators for automobile exhaust waste heat recovery

Annular thermoelectric generators (ATEGs), matched well with the exhaust pipe in geometry, are proposed to recover the heat from automobiles. A theoretical model was constructed to assess the performance of automotive exhaust ATEGs (AEATEGs), where a finite element method was used to incorporate the temperature variation and temperature-dependent properties. The local pressure drop as to the change of cross-section area and shape was considered. Performance comparison with commonly used automotive exhaust flat-plate thermoelectric generators (AEFTEGs) was conducted. Also, the effects of flow arrangement and operating parameters were clarified. Results show that the performance of AEATEGs outperforms AEFTEGs, with the net power on average 1.1% higher. With increasing cooling medium flow rate, the net power increases until attaining a maximum and decreases afterwards. A flow rate of 0.05 kg/s is preferred for the compromise of coolant temperature rise and tank volume. In light of a large temperature drop from exhaust to generators, a simple strategy, inserting a hollow cylinder into heat exchanger, was developed and its effectiveness was evaluated. The maximum enhancement in net power of 214.0% is exhibited, but which reduces notably with increasing exhaust flow rate. For gasoline automobiles, a cylinder with dimensionless diameter of 0.8 is recommended.

A Model for SynbioticActivity Evaluation: Static and Continuous Co-Culture Fermentation of BifidobacteriumAdolescentis ATCC 15703 and Bacillus Cereus ATCC 9634

In this study, the ability of a probioticstrain (BifidobacteriumadolescentisATCC 15703) to inhibit the growth of the common food contaminantBacilluscereusATCC 9634was studied, both individually and as part of a synbiotic with FOS during batch or continuous fermentation (flow fermentation). The conditions of the flow fermentation corresponded to the parameters of the human large intestine: maintaining a pH of 6.8; anaerobiosis; and a medium flow rate of 0.04 h−1. Bifidobacteria and bacilli were co-cultivated on a prebiotic carbohydrate substrate (10 g/L) and the prebiotic was replaced with glucose (10 g/L).The results of the batch and flow fermentation were compared.The synbiotic efficacy of the probioticBif. adolescentisand the prebiotic FOSagainst the common food contaminantBac. cereuswas shown for all conditions. Fermentation of a pure culture of bifidobacteria with varying prebiotic concentrations (2, 5, 10, 15 and 20 g/L) was carried out to study the state of dynamic balance. It was demonstrated that 48 hours is enough to achieve stable dynamic balance.Prebiotics were co-cultivated with varying carbohydrate concentrations of 5, 10, and 15 g/L.The results showed that increasing the prebiotic concentration increased the duration of the lag-phase and reduced the final number of bacilli.
 Keywords: probiotics, prebiotics, synbiotics, gastrointestinal tract modeling, antagonism, co-culture fermentation

Design and characterization of a semi-open dynamic chamber for measuring biogenic volatile organic compound (BVOC) emissions from plants

Abstract. With the accumulation of data about biogenic volatile organic compound (BVOC) emissions from plants based on branch-scale enclosure measurements worldwide, it is vital to assure that measurements are conducted using well-characterized dynamic chambers with good transfer efficiencies and less disturbance on natural growing microenvironments. In this study, a self-made cylindrical semi-open dynamic chamber with a Teflon-coated inner surface was characterized both in the lab with standard BVOC mixtures and in the field with typical broadleaf and coniferous trees. The lab simulation with a constant flow of standard mixtures and online monitoring of BVOCs by proton transfer reaction time-of-flight mass spectrometry (PTR-ToF-MS) revealed lower real-time mixing ratios and shorter equilibrium times than theoretically predicted due to wall loss in the chamber and that larger flow rates (shorter residence times) can reduce the adsorptive loss and improve the transfer efficiencies. However, even when flow rates were raised to secure residence times of less than 1 min, transfer efficiencies were still below 70 % for heavier BVOCs like α-pinene and β-caryophyllene. Relative humidity (RH) impacted the adsorptive loss of BVOCs less significantly when compared to flow rates, with compound-specific patterns related to the influence of RH on their adsorption behaviour. When the chamber was applied in the field to a branch of a Mangifera indica tree, the ambient–enclosure temperature differences decreased from 4.5±0.3 to 1.0±0.2 ∘C and the RH differences decreased from 9.8 ± 0.5 % to 1.2±0.1 % as flow rates increased from 3 L min−1 (residence time ∼4.5 min) to 15 L min−1 (residence time ∼0.9 min). At a medium flow rate of 9 L min−1 (residence time ∼1.5 min), field tests with the dynamic chamber for Mangifera indica and Pinus massoniana branches revealed enclosure temperature increase within +2 ∘C and CO2 depletion within −50 ppm when compared to their ambient counterparts. The results suggested that substantially higher air circulating rates would benefit by reducing equilibrium time, adsorptive loss, and the ambient–enclosure temperature and RH differences. However, even under higher air circulating rates and with inert Teflon-coated inner surfaces, the transfer efficiencies for monoterpene and sesquiterpene species are not so satisfactory, implying that emission factors for these species might be underestimated if they are obtained by dynamic chambers without certified transfer efficiencies and that further efforts are needed for field measurements to improve accuracies and narrow the uncertainties of the emission factors.

Experimental study on boiling heat transfer in negative-pressure flowing water in a vertical annular tube

To study energy recovery from low temperature wastewater during industrial production, a water-boiling heat transfer experimental device was built. A casing evaporator with a length of 1450 mm, an inner tube diameter of 30 mm, and an annular space gap of 14.2 mm is taken as the main research object. The boiling heat transfer characteristics of water in the annular tube area of the casing evaporator were experimentally studied by adjusting the inlet temperature (60? 85?C) of hot water and the pressure in the annular tube (12.1-57.6 kPa). The results show that, as the pressure of the system decreases, the boiling phenomenon in the annular tube becomes more intense and the convective heat transfer coeffi-cient increases. The boiling flow and average surface convective heat transfer enhancement rates, ? , were 2.2 and 1.5 when an initial pressure of 1 kPa was used. When the flow rate of the working medium in the annular tube was 1.69 kg?m2/s, the convective heat transfer coefficient gradually increased with the temperature and then stabilized when the inlet temperature reached between 80?C and 85?C. These results reveal the characteristics of boiling-water heat transfer in an annular tube and aid in the design of heat pipe systems for waste-heat recovery.

Experimental Studies on Water‐Based Al2O3 Nanofluid to Enhance the Performance of the Hybrid Collector

Many research and significant worldwide efforts have been made to combat climate change. The purpose of this research was to maximize the productivity of a flat‐plate hybrid collector with two kinds of cooling medium, namely water and water‐based Al2O3 nanofluid. Effects of single‐volume concentration (0.1%) of Al2O3 nanoparticles and four types of volume flow rates such as 0.5, 1.0, 1.5, and 2.0 litres/minute (LPM) were also examined which found that the best performance is achieved with 2.0 LPM. The experimental results found that the hybrid collector significantly depends on solar radiation, the surface geometry of the cooling channels, and the volume flow rates of the working medium. In addition, the performance of the hybrid collector improved with increasing volume flow rate. Maximum glazing surface temperature has been attained by water collector was 68.2°C, whereas water‐based nanofluid has achieved its glazing surface temperature 63.8°C. As a result, the life of the solar panel has been increased significantly. This occurred because an increase in the volume flow rate increased the turbulence of the working medium, thus resulting in better performance of the hybrid collector. Besides, the results also showed that the distribution of working medium in the channel had played a major role in the heat transfer rate. The thermal efficiency was found to vary from 13.9% to 60.7% for all the four‐volume flow rates of water. Similarly, thermal efficiency was attained from 16.8% to 79.4% for all the four‐volume flow rates of Al2O3 nanofluid.

Heat transfer in a novel microwave heating device coupled with atomization feeding

The heat transfer characteristics of the microwave heating coupled with atomization feeding were investigated using ethanol as the spray medium on a pressure swirl nozzle. The effects of spray height, flow rate and temperature on the sauter mean diameter of atomized droplets were examined. The results showed that the droplet sauter mean diameter was 12-130 ?m, which increased with the spray height and decreased with the flow rate and temperature of spray medium. Through the fitting of the experimental data, the dimensionless correlation of the droplet sauter mean diameter which was based on orifice diameter, Reynolds and Ohnesorge numbers was obtained. The calculated results were basically consistent with the experimental data within 15% error. The heat transfer characteristics of atomized droplets on high temperature surface of SiC bed heated by microwave were then investigated. The effects of spray flow rate, spray height, and spray temperature on the heat transfer characteristics were examined. The power of spray heat transfer decreased with the temperature and increased with the spray flow rate and spray height. The dimensionless correlation to describe the heat transfer characteristics of atomized droplets on the high temperature SiC surface under the microwave heating was obtained which included thermophysical properties of spray medium, spray parameters, and temperatures of the high temperature bed surface and spray medium, with the error of ?20%. These correlations can be used to predict the sauter mean diameter of the atomized droplets and the power of spray heat transfer in the microwave heating process.

Experimental study on heat transfer in a model of submerged combustion vaporizer

• Heat transfer experiment of submerged combustion vaporizer (SCV) model is conducted. • The shell-side, tube-side and overall heat transfer coefficients are obtained. • The average of shell-side heat transfer coefficient is about 300 W/(m 2 ·°C). • Two simple empirical correlations are developed for the overall tube-side heat transfer. The submerged combustion vaporizer (SCV) is widely used in the peak shaving of liquefied natural gas (LNG) supply. It is believed that SCV will have a great application prospect with the implementation of the peak-shaving policy of natural gas in China. SCV injects the flue gas after combustion directly into the water bath from its bottom, causing gas disturbance and two-phase flow in the water bath. The shell-side flow and heat transfer become unclear because of the gas disturbance. There is a lack of relevant theoretical basis in this regard. In order to master the operation mechanism of SCV, an experimental research is carried out on a SCV model which has the same structure and function as the actual small-size SCV. The shell-side, tube-side and overall heat transfer coefficients are obtained, and the influences of operation parameters on the heat transfer are investigated. The results indicate that in the range of the experimental parameters, the shell-side heat transfer coefficient is almost not affected by the frontal gas velocity and Reynolds number of the flue gas at orifices, and the average value is about 300 W/(m 2 ·°C). Meanwhile, the higher the flow rate and pressure of the tube-side medium, the greater the overall heat transfer coefficient. In addition, it is observed that if the gas disturbance stops, the heat transfer deterioration will occur. Finally, two simple empirical correlations are developed for the overall tube-side heat transfer. This study provides support for the design and application of SCV.

Investigation of equilibrium CO2 solubility in 35 wt% aqueous 1-(2-aminoethyl) piperazine (AEP) and performance study over monoethanolamine for CO2 absorption

The present study investigates the CO2 absorption capacity of 1-2-(aminoethyl)piperazine (AEP) as a potential solvent for post combustion CO2 capture. The CO2 absorption performance has been evaluated in terms of Equilibrium CO2 solubility at varied temperature and pressure range. The CO2 solubility measurement was conducted using high pressure stirred autoclave reactor within the temperature and Pressure range of (308.15–328.15) and (2–200) kPa respectively. The equilibrium CO2 solubility data are further correlated using semi-empirical model and equilibrium based Modified Kent-Eisenberg model which shows a better agreement with the generated experimental data. In addition to this, a comprehensive parametric study was also carried out in Aspen-Plus Platform to evaluate the performance of proposed solvent over conventional solvent monoethanolamine (MEA). Influence of various important operating parameters such as flow rates of solvent and Gas medium, amine concentration, solvent inlet temperature and (L/G) ratio on the % CO2 removal was studied.

Variable Exposure Portable Perfusion Monitor Using Commercial Vision Processing System-on-Modules (SOMs)

Laser speckle imaging (LSI) has been widely used to image blood flow in biomedical/clinical research. Commercially available perfusion monitoring systems are bulky, expensive and lack portability. Portable devices that perform LSI using custom Digital Signal Processors (DSPs), and smartphones have been proposed to perform single exposure LSI to monitor blood flow. While these can perform LSI, it is difficult to estimate flow rates using single exposure LSI. In this study, we use NVIDIA’s Xavier NX embedded vision processing platform to perform variable exposure LSI to evaluate flow rates in a 3D printed flow phantom. A low-cost Raspberry Pi HQ camera was used to acquire LSI images and the increased sensitivity of the camera allowed images to be captured with exposure times < 1ms. The higher performance of the Xavier NX platform allowed for video-rate LSI imaging (25 ± 2 FPS for spatial and 5 ± 2 FPS for temporal variance images respectively) of the phantom and using variable exposure datasets, slow (2mm/s-6mm/s), medium (6mm/s-12mm/s), and fast (>12mm/s) flow rates were distinguished. Such a platform can extend the use of portable LSI devices in peri-operative, post-operative and other point-of-care applications as this platform can be commercialized into a tablet-like form factor for convenient portable operation.

A Feasible Zone Analysis Method with Global Partial Load Scanning for Solving Power Flow Coupling Models of CCHP Systems

Heat exchanger systems (HXSs) or heat recovery steam generators (HRSGs) are commonly used in 100 kW to 50 MW combined cooling, heating, and power (CCHP) systems. Power flow coupling (PFC) is found in HXSs and is complex for researchers to quantify. This could possibly mislead the dispatch schedule and result in the inaccurate dispatch. PFC is caused by the inlet and outlet temperatures of each component, gas flow pressure variation, conductive medium flow rate, and atmosphere condition variation. In this paper, the expression of PFC is built by using quadratic functions to fit the nonlinearity of thermal dynamics. While fitting the model, the environmental condition needs prediction, which is calculated using phase space reconstruction (PSR) Kalman filter. In order to solve the complex quadratic dispatch model, a hybrid following electricity load (FEL) and following thermal load (FTL) mode for reducing the dimension of dispatch model, and a feasible zone analysis (FZA) method are proposed. As a result, the PFC problem of CCHP system is solved, and the dispatch cost, investment cost, and the maximum power requirements are optimized. In this paper, a case in Jinan, China is studied. The PFC model is proven to be more precise and accurate compared with traditional models.

Neuroprotective role of human neuritin 1 on axotomized human eyes pressurized using the Translaminar Autonomous System

Purpose: Primary open-angle glaucoma is a leading cause of vision loss worldwide characterized by retinal ganglion cell death (RGC) and visual field loss. Glaucoma is most commonly associated with an increase in intraocular pressure (IOP), and current clinical management is limited to lowering intraocular pressure. We have previously shown that the secreted human protein neuritin 1 (NRN1) exhibits neuroprotection, regeneration, and preservation of RGC function after RGC axonal injury. We propose to overcome RGC degeneration by over-expressing NRN1 in our novel ex-vivo perfused pressurized Translaminar Autonomous System (TAS). &#x0D; Methods: Human donor eyes were obtained from eye banks. To model glaucomatous conditions, dissected human posterior eye cups were cultured in the TAS model with IOP:ICP conditions of 16:12 mmHg over 6 days. Flow rate of perfusion medium to the interior and exterior (around optic nerve) of the eye cup (IOP and ICP, respectively) was controlled by automated pumps to induce the translaminar pressure gradient.We assessed survival of RGCs with and without hNRN1 treatment by TaqMan array analysis of apoptosis/inflammatory markers (retina). Expression of FN and COLIV was examined from conditioned medium of both groups by Western analysis. &#x0D; Results: We successfully maintained IOP: ICP differentials over 6 days. The RGCs degenerated faster in non-treated conditions compared to NRN1 treated eyes. In contrast to control, NRN1-treated group displayed differential expression of FN and COLIV. We observed dysregulated expression of GFAP, BAX and TLR4 expression between control and experimental conditions. &#x0D; Conclusion: We utilized our unique TAS model to recreate the human optic nerve head environment of elevated translaminar pressure for testing a unique neuroprotective and regenerative gene therapy. Using this approach, we hope to identify human Neuritin 1 as a therapeutic gene to save the visual neurons and develop a new treatment for glaucoma.

A new software program for monitoring the energy distribution in a thermal waste treatment plant system

The paper presents a novel system for monitoring the operation of a thermal waste treatment plant. The computer program is based on measurements of pressure, temperature, and mass flow rate of the working medium. The boiler efficiency is calculated using an indirect method. Thermal online calculations of the boiler combustion chamber make it possible to determine the heat flow rate to the evaporator. Based on the energy balance of the boiler evaporator, the superheated steam mass flow rate is determined, taking into account the mass flow rates of water injected into steam attemperators. By comparing the calculated and measured value of steam mass flow rate, the calorific value of the fuel fed is determined. The developed system enables monitoring of energy flow rates in individual elements of the power unit, taking into account losses in the boiler and turbine condenser. The following parameters are determined online, the efficiency of the boiler and the entire incinerator, heat losses in the boiler and the turbine condenser, as well as the heat flow rate, supplied to the municipal district heating system. By monitoring the plant operation, it is possible to adjust online the optimum excess air ratio.

P.171: Long-term Study of Vascularized Pancreas-on-chip

Microfluidic Systems and Bioengineering. Diabetes (type 1 and type 2) is a chronic disease that may lead to various complications, such as vasculopathy, neuropathy, retinopathy or diabetic foot ulceration, which heavily affect patients’ quality of life. To emulate such a complex disease, we develop different organs-on-chips with human cells and focus our efforts on the possibility of long-term study of this complex system up to 1 month. We created a specific microfluidic chip in which endothelialized Langerhanoids (or pseudo-islets) produced off-line are embedded in a finely controlled microenvironment with favorable conditions for vascularization, perfusion and long-term production of insulin. A key parameter for long-term stability is the quality of the endothelial network.We therefore study this by varying parameters such as cellular ratio (endothelial cell concentration vs support cell concentration), culture medium composition, fluidic geometry and flow rate. By analyzing images from bright-field and fluorescence microscopy, we quantify the quality of the endothelial network, which allows us to determine optimal conditions for its development and long-term stability. At this stage, we achieve to manage a stability for more than 40 days under flow.This new generation of organoids-on-chip and the associated experimental setup allow studying and discussing the value of the vascularization in OoC systems aiming to maintain long-term stability and biological functionality of the system. We thank the French Carnot Institute and CEA for funding.

Weight loss and burst testing investigations of sintered silicon carbide under oxidizing environments for next generation accident tolerant fuels for SMR applications

Accident tolerant fuel (ATF) cladding is one of the most active area for research to advance the global contribution of nuclear energy since ATF will ensure and enhance the reactor safety allowing long refueling cycles and higher burnup. Silicon Carbide (SiC) is one material that can potentially be a solution to this long standing challenge. This study offers both computational reactor physics modeling and experimental investigation to examine the behavior of SiC in nuclear reactor environment. With recent interest in small modular reactors (SMR), this study selected SMR compact core as a reference assembly for Computational Burnup Modeling (CBM). Results of CBM suggest that SiC cladding will provide the highest burnup and maximum uranium utilization. Therefore, subsequent experimental investigations were focused on SiC only. Rhode Island Nuclear Science Center (RINSC)’s nuclear research reactor was used to investigate effects of irradiation on sintered tubular SiC material samples under pure steam at 1 atm, initially at 120 °C, followed by high temperatures between 850 °C and 1350 °C to simulate harsh reactor environment.Experimental analyzes of (a) weight loss and (b) burst testing are considered for SiC samples. For the weight loss experiment, we have considered both types of samples: (1) Non-irradiated and (2) Neutron-irradiated samples. Weight loss was found to be dependent on sample geometry. Irradiated samples show ∼2%–10% higher weight loss per area than that of the non-irradiated samples. Besides, considering the medium flow rate (less than 10 g/min), it has been observed that the irradiated samples exhibit ∼10%–40% higher weight loss than that of the non-irradiated samples over temperatures of 120 °C, 850 °C to 1350 °C. It is also seen that material loss rates are generally more sensitive at higher temperatures than at lower temperatures, and irradiated samples are more prone to weight loss. Furthermore, for the burst testing experimental investigations, experiments were conducted for (1) As-received samples (2) Non-irradiated samples and (3) Irradiated samples. Considering the three types of samples, it was observed that the maximum and minimum peak load values are ∼70% higher and ∼60% lower than the average peak load while fracture hoop stress is consistently ∼70%–75% higher than the internal pressure for all as-received samples. Experimental and computational investigations suggest that SiC is a viable candidate for ATF cladding material.

COMPARISON OF OPTIONS FOR THE HEAT DISTRIBUTION NETWORK OF THE RESIDENTIAL NEIGHBORHOOD

The comparison of heat losses by pipelines of an extensive residential neighborhood heating system for two options of the distribution network was carried out for a residential neighborhood in Kharkov. The proposed configuration of the heating network differs from the existing ("basic") one in using of the law of heating medium flow rate variation along the heat pipe length. This law takes into account increased flow rate of heating water through branches at the initial sections of the pipeline. The actual flow rate distribution is approximated by a step function. The difference in the laws of flow rate variation is taken into account by the exponent value. The calculation of heat losses was carried out for underground pipelining in non-accessible tunnels. The temperature of heat line water is taken to be the corresponding to the design outdoor air temperature for heating according to the temperature schedule of the heating network. Specific heat losses by pipelines in heat network sections are considered to be at the standard level for non-accessible tunnels. The soil temperature at the depth of the heat pipe axis is taken equal to 5°C. Heat losses by the structural elements of the heat network are taken into account by a factor of 1.15. The variation of the flow rate and temperature of network water in rated pipeline sections is considered in the analysis. The water flow rate at the sections was found based on the design thermal loads of connected buildings.&#x0D; It is shown that when choosing the configuration of the distribution network of the heating system of a group of buildings, preference should be given to the option with a lower value of the exponent in the equation for heating medium flow rate variation along the length of the main line of the network. For extensive heating networks, this can be achieved by connecting as many buildings as possible to the heating network sections close to a heat supply station. An increase in the network water flow rate through the branches at the initial sections of the pipeline ensures a decrease in heat losses by the network pipelines. For the considered part of a residential neighborhood, the decrease in heat loss at the design outdoor air temperature for heating is 5.5 %.

A Comparative Study of Intraoperative Haemodynamic Changes with Low and Medium Fresh Gas Flow Rates in Patients Undergoing Abdominal Surgeries

Decreasing the fresh gas flow rate during anaesthesia in surgeries may minimise costs, reduce environmental pollution and preserve heat and humidity in the respiratory system.

Understanding the Characteristics of Pedestrians when Passing Obstacles of Different Sizes: An Experimental Study

The aim of this study is to understand the collective movements of individuals and to observe how individuals interact within a physical environment in a crowd dynamic, which has drawn the attention of many researchers. We conducted an experimental study to observe interactions in the collective motions of people and to identify characteristics of pedestrians when passing obstacles of different sizes (bar-shaped, 1.2 m, 2.4 m, 3.6 m and 4.8 m), going through one narrow exit and employing three different flow rates in walking and running conditions. According to the results of our study, there were no differences in collision-avoidance behaviour of pedestrians when walking or running. The pedestrians reacted early to the obstacles and changed the direction in which they were walking by quickly turning to the left or to the right. In terms of the speed of the pedestrians, the average velocity was significantly affected while performing these tasks, decreasing as the size of the obstacle increased; therefore, the size of obstacles will affect flow and speed levels. Travel time was shorter when participants were in the medium-flow rate experiments. In terms of the distance of each individual’s travel, our data showed that there was no significant difference in all the flow rate experiments for both speed levels. Our results also show that when the pedestrians crossed an obstacle, the lateral distance averaged from 0.3 m to 0.7 m, depending on the flow rate and speed level. We then explored how the body sways behaved while avoiding obstacles. It is observed that the average sway of the body was less in the high-speed conditions compared to the low-speed conditions – except for the HF &amp; 4.8 m experiment. These results are expected to provide an insight into the characteristics of the behaviour of pedestrians when avoiding objects, and this could help enhance agent-based models.

Diagnostics of a Domestic Hot Water Storage Tank under Operating Conditions

This paper presents a new method for the diagnostics of a hot water storage tank under operating conditions. Depending on the operating point of the tank, the method enables determination of thermal conductivity coefficients of the coil heat exchanger, which allows us to determine the intensity of heat transfer between the transfer medium and water in the tank as well as of tank walls, which consequently enables determination of heat losses to the environment. Furthermore, the dynamic properties of the tank may also be determined by applying this method. The advantage of this method is possibility of analyzing changes in the material constants of the coil heat exchanger, tank walls, and dynamic properties of the tank as a function of mass flow of the medium supplying the coil heat exchanger. The possibility of determining coefficients of thermal conductivity as well as the inertia of tank and exchanger, based on temperature measurements acquired in operating conditions is a novelty in this paper. Knowing the variability of material constants and of dynamic properties of the tank as a function of medium flow rate allows multicriteria optimization to be performed which, with a conventional design of the tank, results in a reduction of up to 10% in the time taken to prepare domestic hot water.

A blended empirical shot stream velocity model for improvement of shot peening production

Peening intensity and coverage are vital measurement outputs to quantify the quality of a peening process in the surface enhancement operation of metal parts. In practice, these parameters can only be measured offline upon process completion, which is not suitable for online tracking and operation. Instead, shot stream velocity can be used as a real-time monitoring parameter to bridge operational inputs to the outputs. As such, a robust and accurate shot stream velocity model is needed for real-time tracking. In this study, we propose a blended practical model for shot stream velocity to address the issues. The model is constructed using a regression algorithm based on the blended candidate functions, which are developed from the experimental data and nature of the particle-air flow inside the system. The obtained model is validated against the experimental data for ASR 70 media type for different operating conditions of the inlet airflow pressure and media flowrate. Calculated velocities are in good agreement with the measurements. In addition, the developed model is applied to predict the shot stream velocity for ASR 230 media type, as well as to evaluate the peening intensity and coverage for different media types under different operating conditions. The predicted results are comparable to the measurement data under the same operating conditions. The maximum relative error of the predicted shot stream velocity and measurement velocity is about 5%, while the maximum error in peening intensity is about ±0.0065 mmA. Furthermore, a single-input and single-output model-based control is developed based on the proposed shot stream velocity model. The developed control system is robust, accurate, and reliable. It implies that the developed model can be used to provide the necessary information, as well as to develop the optimal process control system to improve and accelerate the peening processes for cost and time reduction of actual production.

METHOD FOR CALCULATING THE NUMBER OF THROTTLE ELEMENTS OF THE MULTI-TOOTH DORN

The method for calculating the parameters of the cylindrical throttling elements of the tipping teeth of a multi-toothed mandrel has been performed, which makes it possible to provide the required volume and distribution of the working medium flow supplied to the mandrel in the process of processing deep holes of long cylinders and to substantiate the division of the total flow into several different streams that provide throttling of the lubricating-cooling liquid (Coolant) when used in a lubricating and cooling technological environment (SOTS). It is assumed that the processing is carried out on the principles of combining the processes of vortex milling and surface plastic deformation (SPD) by the methods and method of helical interpolation presented in the description of the monograph. The research results based on the developed methodology for calculating the flow rate of the working medium in cylindrical throttling elements allows for further improvement of existing methods for processing deep holes, including improving the quality of high-precision precision pipes.