Orifice Plate Research Articles

Cold Expansion Strengthening of 7050 Aluminum Alloy Hole: Structure, Residual Stress, and Fatigue Life

The 7050 aluminum alloy orifice plate is extruded and strengthened by the cold expansion process of slotted bushing holes. A three-dimensional finite element model was established for cold expansion strengthening of holes, and the residual stress distribution of 7050 aluminum alloy orifice plates is studied after cold expansion. The influence of different relative extrusion amounts and different sample thicknesses on the residual stress around the sample hole was analyzed, and the relationship between the extrusion amounts and the thicknesses of the substrate and the residual stress was obtained by analysis. The research results indicate that the cold expansion process of slotted bushing holes can enhance the residual stress distribution around the hole and form a strong residual stress layer. As the amounts of extrusion increase, the residual stress tends to increase, reaching the maximum when the amounts of extrusion are 4%. The residual stress on the surface of the extrusion inlet increases with the increase in the thickness of the substrate. Within the range of 3%-4% of the extrusion amounts, with the continuous increase of the extrusion amounts, the fatigue life has been substantially enhanced, and the number of fatigue life is more than 3 times that of the empty plate fatigue test.

Application of Effective Orifice Jet Length for Treating SST Effluent of STP by Hydrodynamic Cavitation

Advanced oxidation process in general and hydrodynamic cavitation, in particular, has emerged as a promising technology for the treatment of wastewater in the last few years as the process is energy-efficient and cost-effective. In this process, cavities are generated due to local pressure drops caused by constrictions. This work aimed to investigate the potential of hydrodynamic cavitation as a tertiary treatment to the secondary sedimentation tank effluent of a sewage treatment plant, with two laboratory-scale experimental setups having an orifice plate of a 1 mm diameter hole. The process dependency was estimated by optimizing inlet pressure (0.8 bar for setup I and 5 bar for setup II). Moreover, effective orifice jet length was varied to investigate the impact of fluid buoyancy force on expansion and collapse of a cavity on the chemical oxygen demand removal and disinfection. At L2 length (two-thirds of the original length), both setups can degrade the organic and inorganic pollutants to the maximum extent. With the optimum condition in setup II, maximum COD, TSS, and fecal coliform degradation were 80.47%, 62.83%, and 52.27%, respectively, compared to setup I.

Effect of slot-shaped pins on heat transfer performance in the extended jet impingement cooling

In this study, effects of heat transfer performance on the roughened target surface with slot-shaped pins (SSP) were numerically investigated using an in-line array of extended jet impingement cooling models. The influence of pin heights on convective heat transfer for variable nozzle lengths, different pin arrangements, and Reynolds numbers (Re) in a rectangular channel flow was examined. The pins were located in a staggered and circular pattern. The numerical solution procedure has been verified by comparing numerical results with the available experimental data in the literature. The simulations were conducted with shear stress transport k-ω with low-Re correction turbulence model considering boundary conditions. The numerical model reasonably predicted heat transfer and pressure drop for flat plates and roughened plates with pins. Average Nusselt numbers on the surface were determined numerically using the model validated with experimental data for different dimensionless pin heights Hp/Dj (0.167, 0.417, and 0.667), various pin arrangements (R1, R2, R3), dimensionless nozzle lengths Gj/Dj (1.0, 2.0, and 6.0), and Re numbers (16250, 27100, and 32500). Numerical results were compared with the orifice plate; in other words, the conventional jet impinging configuration (Gj/Dj= 6.0 and Hp/Dj= 0). When the system's flow characteristics and performance evaluation criterion were considered, optimum geometric parameters for all Re were determined as Hp/Dj= 0.167 and R1_Gj/Dj= 1.0. Obviously, pin-roughened surfaces strongly affect the mean convective heat transfer and the homogeneity of the local heat transfer in extended jet impinging cooling systems. In this way, the negative effect of thermal stresses on the interested surface can be reduced, and the life of the material can be extended. Since the development of additive manufacturing technologies makes it possible to use these geometries in the internal cooling channels of gas turbine blades, a significant contribution will be made to the literature as a result of this study.

Numerical simulation for condensation in the presence of noncondensable gas in the condenser with a multi-channel structure

Condensation in the presence of noncondensable gas is of interest to the passive containment cooling system in the nuclear power plant. Most researches focus on the heat transfer characteristics of condensation in an individual vertical tube or a parallel tube bundle. However, the influence of the condenser structure on condensation heat transfer is rarely considered in previous works. Thus, a numerical simulation was conducted for condensation in the presence of NCG in a condenser composed of two headers and 158 condenser tubes. A steady three-dimensional model was developed to predict the NCG distribution and the heat transfer performance of the condenser when the PCCS loop was stably running. The fluid inside the condenser was regarded as a single-phase mixture composed of steam and air, and the liquid film was evaluated by the Eulerian Wall Film model. The results indicated that the air tends to accumulate in the middle of the condenser tubes rather than the headers. The fluid flow in most of the tubes was blocked, so the heat transfer coefficients of pure steam and the steam-air mixture were lower than expected. An orifice plate was further designed to optimize the pressure and flow field in the PCCS condenser. The effect of the optimization was quantitatively evaluated. The results showed that the heat transfer performance of the condenser was improved by up to 87.8% with the orifice plate.

Performance improvement prediction of push chain moist-mix concrete spraying machine employing orifice plate

Performance improvement prediction of push chain moist-mix concrete spraying machine employing orifice plate

Experimental study on prediction model of wet gas pressure drop across single-orifice plate in horizontal pipes in the low gas phase Froude number region

The pressure drop prediction of wet gas across single-orifice plate in horizontal pipes had been solved satisfactorily under an annular-mist flow in the upstream of orifice plates. However, this pressure drop prediction is still not clearly determined when the upstream is in an intermittent flow or stratified flow, which is corresponding to a region of low Fr G (gas phase Froude number) in the flow pattern map of wet gases. In this study, the wet gas pressure drop across a single-orifice plate was experimentally investigated in the low Fr G region. By the experiment, the flow pattern transition in the downstream of single-orifice plates, as well as the effects of Fr G and Fr L (liquid phase Froude number) on Φ G (gas phase multiplier), were determined and compared when the upstream is in the flow pattern transition and the stratified flow region, respectively. Prediction performances were examined on the available pressure drop models. It was found that no model could be capable of jointly predicting the wet gas pressure drop in the low Fr G region with an acceptable accuracy. With a new method of correlating Fr G and Fr L simultaneously, new correlations were proposed for the low Fr G region. Among which the modified Chisholm model shows the best prediction accuracies, with the prediction deviations of Φ G being within 7% and 3% when the upstream is in flow pattern transition and stratified flow region, respectively.

Vibration analysis and reduction optimization study of a reciprocating compressor piping system under multi-boundary coupling

In response to the characteristics of variable working conditions of shale gas extraction, in order to ensure the operational safety of shale gas compressors, this paper takes a certain type of shale gas compressor piping system in Weiyuan as the research object. Based on the plane wave theory and vibration theory, the research on the distribution law of gas pulsation of the piping system and the vibration characteristics under multi-boundary coupling was carried out, and the area of gas pulsation exceeded and the part of amplitude exceeding the piping system were locked. The vibration test of the piping system was carried out and the results showed that the amplitude of the piping system exceeded the standard and the agreement between the test and simulation results was high, which verified the correctness of the simulation model. In response to the problem of excessive vibration of the piping system, orifice plate aperture ratio orthogonal test and piping system structure optimization were carried out. After optimization, the amplitude of gas pulsation and vibration was significantly reduced, and they all met the requirements of the API 618 standard, which reduced the risk of structural damage to the piping system and improved the reliability and safety of the shale gas compressor unit.

Sulfadiazine degradation by combination of hydrodynamic cavitation and Fenton-persulfate: parametric optimization and deduction of chemical mechanism.

This paper reports the degradation of the sulfadiazine (SDZ) drug with a hybrid advanced oxidation process (AOP) of heterogeneous α-Fe2O3/persulfate coupled with hydrodynamic cavitation. The major objectives of the study are parametric optimization of the process and elucidation of the chemical mechanism of degradation. The optimum conditions for maximum SDZ degradation of 93.07 ± 1.67% were as follows: initial SDZ concentration = 20ppm, pH = 4, α-Fe2O3 = 181.82mg/L, Na2S2O8 = 348.49mg/L, H2O2 = 0.95mL/L, inlet pressure = 0.81MPa (8atm), orifice plate configuration: hole dia. = 2mm and number of holes = 4. Density functional theory (DFT) calculations revealed that the atoms of SDZ with a high Fukui index (f 0) were potentially active sites for the attack of •OH and [Formula: see text] radicals. Fukui index calculation revealed that atom 11N has a higher value of f 0 (0.1026) for oxidation at the α-amine group of the sulfadiazine molecule. Degradation intermediates detected through LC-MS/MS analysis corroborated the results of DFT simulations. Using these results, a chemical pathway has been proposed for SDZ degradation.

Stability performance of series coupled natural circulation system with different operating procedures

Series coupled natural circulation system with the last loop being an open-air loop finds application as an infinite mission time passive decay heat removal system in nuclear power plants and solar thermal systems. Hence the stability behavior of series coupled rectangular loops with horizontal heater and horizontal cooler orientation was experimentally studied. The loop was subjected to various operating procedures viz., start up from rest, power raising from a stable steady state and power step down from an unstable state to witness that the stability threshold was not a unique value, thus confirming the existence of a hysteresis phenomenon. The stability threshold enhancement of the system with orifice plates was maximum for the lowest orifice diameter. The coupled system was chosen with an unstable first loop and the instability was found to transmit from loop#1 to the subsequent loops. However, the oscillation amplitude was highly attenuated and seemed to be nearly stable in the 2nd and 3rd loop without any flow reversals even when the first loop was unstable with chaotic bidirectional pulsing. In case of bi-directional pulsing in loop#1, the heat exchanger between the first two loops operated alternatively in co-current and counter-current mode with no change in the flow direction of loop#2. A delay in the flow initiation was found for start-up from rest, which increased from the first loop to the last loop and decreased with the increase in power input. Further, the numerical simulation with the one-dimensional model reproduced the oscillatory behavior in loop#1, with the predicted stability threshold being considerably lower compared to the experiments. The attenuation of the oscillations in the loop#2 as observed in the experiments could be reproduced. Predicted transients showed practically no oscillations in loop#3 corroborating the experimental observations. The attenuation of the oscillations in loop#2 and the absence of oscillations in loop#3 were attributed to the damping caused by the wall and also due to the higher Lt/D ratio in loop#2 and a vertical air flow channel in loop#3 respectively. The phase plots indicated a near periodic oscillation compared to the highly chaotic pattern in the experiments, presumably due to the higher power at which instability was observed in the experiments. The deviations were also due to the secondary flows being generated in the large diameter loop as the simulation was based on 1D along with the heat loss being neglected.

Effect of an orifice plate on the explosion behaviors of H2–N2O mixtures

The explosion characteristics of H2–N2O over a wide range of equivalence ratio (φ) at a reduced pressure were studied experimentally in a cylindrical explosion vessel. Two orifice plates with the blockage ratios of 0.4 and 0.6 were employed to characterize the influence of an obstacle on the explosion behaviors. The experimental results showed that maximum explosion pressure could be higher than the adiabatic value due to the potential of flame acceleration and deflagration to detonation transition (DDT). The maximum explosion pressure was increased by the orifice plate at the fuel-lean side due to the flame instability while decreased at the fuel-rich side. This means that the roles played by the orifice plate are different for affecting the maximum pressure. The maximum pressure rise rate ((dp/dt)max) was increased by introduction of an orifice plate due to the turbulence-generator effect. The maximum (dp/dt)max was obtained at φ = 0.6, indicating that the flame instability rather than the adiabatic explosion pressure or laminar burning velocity plays a leading role.

Design and investigation of a resonant piezoelectric pump with high output pressure using a displacement-amplifying vibrator

A resonant piezoelectric pump using a displacement-amplifying vibrator is proposed in this paper to improve the output pressure of the piezoelectric pump. The piezoelectric pump is composed of a displacement-amplifying vibrator and a pump body. The displacement-amplifying vibrator consists of two amplifiers and two piezoelectric stacks. The pump body comprises a piston shaft, an orifice plate, a valve body, check valves and a runner plate. A clearance exists between the piston shaft and the orifice plate. A groove is designed on the piston shaft, and the pump body is sealed by O-rings. The displacement-amplifying vibrator works in the resonant state, which has a large output amplitude. In this paper, the working principle of the piezoelectric pump is introduced and the influencing factors of output pressure of the piezoelectric pump are theoretically analyzed. The resonant frequency and stiffness of check valves with different thicknesses are simulated and compared, and three displacement amplifiers are designed and simulated. Prototypes of piezoelectric pump are made, and the effect of valve thickness, the diameter of piston shaft, and the displacement-amplifying vibrator is experimentally investigated. The experimental results show that the piezoelectric pump prototype with displacement-amplifying vibrator 3, 10 mm piston shaft and 0.05 mm-thick check valve has the maximum output pressure. Under the driving voltage of 500 Vpp, the maximum output pressure is 4.73 MPa, and the maximum flowrate is 65.7 ml min−1.

Numerical simulation of the pressure distribution in the ventilating channels with a mixed flow fan

Flow characteristics in the pipeline which includes the heat exchanger, mixed flow fan, and straight tube are investigated using the RNG k-ε turbulence model base on the porous media model and the dynamic mesh model. The pressure measuring point is arranged at a distance of 450 mm from the electric motor having a large dynamic pressure value. A detailed numerical calculation has been performed to study the influence of the main geometry structure on flow structure and the pressure value at multiple locations. At the same volume flow rate, a high number of blades enables a higher total pressure, and a larger blade outlet angle and straight diameter can reduce the maximum pressure at the monitoring position. Dynamic pressure is regarded as the main factor influencing pressure variation. In addition, a smaller inner diameter of the orifice plate can cause a more complicated flow due to the increasing static pressure. Finally, a wind pressure software is integrated based on the pressure images and the fitting curves by C# language. This can help to understander the flow characteristics in the ventilating duct and improve the monitoring ability of the air supply system

Determining airflow obstruction from tracheal sound analysis: simulated tests and evaluations in patients with acromegaly.

To evaluate the ability of tracheal sound analysis (TSA) to detect airflow obstruction, particularly in patients with acromegaly. A simulated analysis compared free airflow conditions with airflow through orifice plates 6, 8, 10 and 12mm in diameter. Based on these results, TSA and spirometry examinations were performed on controls (n = 17) and patients with acromegaly (n = 17). The simulated study showed that airway obstruction and airflow values increased the values of power and a progressive displacement of the spectral distribution towards higher frequencies. In agreement with the simulation, airway obstruction in patients with acromegaly also resulted in increased values of power (p < 0.002) and displacement of the spectral distribution (p < 0.01). Significant associations were observed between the TSA parameters and the spirometry indices of obstruction (p < 0.02). In addition, the TSA parameters achieved adequate diagnostic accuracy (AUC ≥ 0.887). The present study provides evidence that TSA during resting breathing would provide adequate biomarkers of early upper airway changes in patients with acromegaly. TSA is carried out during spontaneous ventilation, requires little from the patient, and is fast and inexpensive. Taken together, these practical considerations and the results of the present study suggest that TSA may improve lung function tests for patients with acromegaly. Summary of the study, overall design flow and the main results obtained.

Novel packed bed reactor designed for Prileschajew epoxidation of fatty acid methyl ester: Intensification of mass/heat transfer

In this work, a packed bed reactor with orifice plates (PBR@OP) was designed and applied to Prileschajew epoxidation. The reactor performance such as mass/heat transfer and reaction characteristics were studied and compared with packed bed reactor (PBR) and stirred-tank reactor (STR). In PBR@OP, the periodical dynamic variation of droplet size was characterized. Liquid-liquid two phases were well mixed at a low flow velocity, resulting in a significant reduction of total reactor length and pressure drop as compared with PBR. The heat transfer coefficient and thermal stability of PBR@OP were analyzed and a method to determine the critical diameter of the reactor for the epoxidation was developed. The continuous epoxidation of fatty acid methyl ester (FAME) in PBR@OP was carried out with a simpler and safer process, and the rate of transfer process and reaction were greatly enhanced as compared with that in STR. This reactor presents an economic choice for the process intensification of continuous epoxidation.

On flapping jets induced by a fluttering film and from circular nozzles of smooth contraction, orifice plate and long pipe

On flapping jets induced by a fluttering film and from circular nozzles of smooth contraction, orifice plate and long pipe

Parametric analysis of orifice plates on measurement of flow: A review

Flow measurement is a process of monitoring flow rate of fluids. Flow measurement is one of the critical processes in many industries, it is essential to carry out a detailed analysis of uncertainties associated with flow measurement. This paper attempts to understand the basics of existing flow measurement techniques and orifice flow meter in particular as it is widely used for measurement of flow due to its industry-friendly characteristics. A detailed review is presented in the paper to understand the dynamics of flow measurement, effects caused on the measurement due to variation in a physical dimension of the orifice like thickness of orifice plate, orifice-hole diameter, number of holes, etc. Discussion is also carried on to understand the influence of parameters like type of fluids, position and type of plate. The parametric effect on the performance of an orifice plate is validated using Computational Fluid Dynamics (CFD) for a better understanding of its dynamic nature.

Comparative study by life cycle assessment of an air ejector and orifice plate for experimental measuring stand manufactured by conventional manufacturing and additive manufacturing

An integral part of the rapid development of modern technologies is additive manufacturing (AM) or three-dimensional (3D) printing, which produces specific products that can replace the classic subtractive methods of machining or conventional manufacturing (CM). This study assessed the manufacturing processes of these two methods during the production of an air ejector and a centric orifice plate using the life cycle assessment (LCA) with the cradle-to-grave method, supported by experimental measurements. In general, the study serves as a tool for the companies for the development of circular economy. This study is specifically focused on and conducted for the industrial sector in the Czech Republic. This study presents a comprehensive assessment of the energy and material flows during the processes of mining, production of semi-finished products, processing of byproducts, and subsequent recycling. Moreover, it includes an assessment of the production of emissions and their effect and impact on the environment and, subsequently, the social aspect. It was found that from a primary energy demand (PED) perspective, AM single build is 30% more demanding in the case without recycling and 27.5% more demanding with the inclusion of the end-of-life phase. Moreover, the impact of AM is greater in four out of six impact categories for the ReCiPe 2016v 1.1 methodology. In addition, for the CML 2001 – Aug. 2016 methodology, AM is greater in four out of five categories. Finally, AM is greater in four out of four impact categories for the EF 3.0 methodology. The study highlights the hypothesis based on the production time for the full build, where from a PED perspective, AM with the end-of-life phase is only 2.76% and 3.89% more demanding with and without the offsetting of time deviation, respectively. The results of this study discuss the potential development and reduction of the burden on the environment during the life cycle of AM, especially during the cooling AM and the production of metallic powder. Although previous studies compared AM and CM were conducted, common and simple rotating components were virtually absent. This study aims to address this problem and arouse interest in the development of the issues presented.

Orifice plate modeling with two-phase multiplier including the effect of the area contraction ratio

The flow of a gas-liquid across the orifice plate occurs a pressure drop. It employs a two-phase multiplier to estimate the average pressure drop. In the present times, the two-phase multiplier does not account for the orifice size, becoming incomplete models. The introduction of the area contraction ratio is the novelty of this paper. The proposed model employs a two-phase multiplier depending on the quality, densities ratio, area contraction ratio, and two constants extracted from experimental databases. The proposed model has a low bias, applicable for densities ratio, (ρL/ρG), of 3.05 to 800 and an area contraction ratio of 0.072 to 1.000.

Cavitation assisted novel method for synthesis of starch nanoparticles

Starch nanoparticles (SNPs) have drawn significant attention by researchers in the last decade because of their unique mechanical properties, renewable nature, low cost and numerous industrial applications. In this paper we present the first detailed study of the use of cavitation under alkaline conditions followed by precipitation for synthesis of rice SNPs. For acoustic cavitation, the effect of sonication time and sonication power and for hydrodynamic cavitation the effect of inlet pressure, number of passes and number of holes of orifice plate on particle size distribution and average particle size of SNPs was investigated. Surface morphology of the native and SNPs was elucidated using scanning electron microscopy. Physicochemical changes in formed SNPs were investigated by FTIR spectroscopy and XRD technique. Acoustic cavitation (30 kHz, 175 W) produced SNPs having size as low as 70 nm in 20 min of sonication time. For hydrodynamic cavitation, higher inlet pressure, higher number of passes and orifice plates with more holes, produced particles with narrow distribution. Combination of alkali and cavitation treatment resulted in formation of SNPs with reduced crystallinity compared to native starch particles. Hydrodynamic cavitation assisted synthesis of SNPs was found to be much more energy efficient compared to acoustic cavitation.

Three-dimensional MHD flow in moderate change ratio orifice

In fusion reactor blanket design, liquid metals are attractive working fluids since it is possible to combine in a single fluid the functions of coolant, tritium carrier and breeder. These electrically conductive fluids flow in the presence of a strong magnetic field, inducing the appearance of Lorentz forces and magnetohydrodynamic MHD effects. Increased pressure loss, particularly in complex geometry elements, is a critical point for blanket design. The MHD flow through an orifice plate made by electroconductive walls (c = 0.01 ÷ 0.1) has been analysed in this paper using ANSYS CFX in the range Re = 108, and Ha = 0 ÷ 300. A wide recirculation region is detected after the flow exits the orifice, with potentially harmful consequences for efficient tritium removal. Large pressure loss occurs in the orifice due to conductive wall and non-negligible axial length. The 3D pressure drop term is characterized through a local resistance coefficient (k) that is found to be k ≈ 0.205 for well conducting walls (c = 0.1) and k ≈ 0.063 for poorly conducting ones (c = 0.01).