scholarly journals Numerical Simulation of Particle Dynamics in a Spiral Jet Mill via Coupled CFD-DEM

Pharmaceutics ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 937
Author(s):  
Satyajeet Bhonsale ◽  
Lewis Scott ◽  
Mojtaba Ghadiri ◽  
Jan Van Impe

Spiral jet mills are ubiquitous in the pharmaceutical industry. Breakage and classification in spiral jet mills occur due to complex interactions between the fluid and the solid phases. The study of these interactions requires the use of computational fluid dynamics (CFD) for the fluid phase coupled with discrete element models (DEM) for the particle phase. In this study, we investigate particle dynamics in a 50-mm spiral jet mill through coupled CFD-DEM simulations. The simulations showed that the fluid was significantly decelerated by the presence of the particles in the milling chamber. Furthermore, we study the particle dynamics and collision statistics at two different operating conditions and three different particle loadings. As expected, the particle velocity was affected by both the particle loading and operating pressure. The particles moved slower at low pressures and high loadings. We also found that particle–particle collisions outnumbered particle–wall collisions.

1996 ◽  
Vol 34 (9) ◽  
pp. 149-156 ◽  
Author(s):  
C. Ratanatamskul ◽  
K. Yamamoto ◽  
T. Urase ◽  
S. Ohgaki

The recent development of new generation LPRO or nanofiltration membranes have received attraction for application in the field of wastewater and water treatment through an increasingly stringent regulation for drinking purpose and water reclamation. In this research, the application on treatment of anionic pollutants (nitrate, nitrite, phosphate, sulfate and chloride ions) have been investigated as functions of transmembrane pressure, crossflow velocity and temperature under very much lower pressure operation range (0.49 to 0.03 MPa) than any other previous research used to do. Negative rejection was also observed under very much low range of operating pressure in the case of membrane type NTR-7250. Moreover, the extended Nernst-Planck model was used for analysis of the experimental data of the rejection of nitrate, nitrite and chloride ions in single solution by considering effective charged density of the membranes.


Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 4008
Author(s):  
Błażej Doroszuk ◽  
Robert Król ◽  
Jarosław Wajs

This paper addresses the problem of conveyor transfer station design in harsh operating conditions, aiming to identify and eliminate a failure phenomenon which interrupts aggregate supply. The analyzed transfer station is located in a Polish granite quarry. The study employs laser scanning and reverse engineering methods to map the existing transfer station and its geometry. Next, a discrete element method (DEM) model of granite aggregate has been created and used for simulating current operating conditions. The arch formation has been identified as the main reason for breakdowns. Alternative design solutions for transfer stations were tested in DEM simulations. The most uncomplicated design for manufacturing incorporated an impact plate, and a straight chute has been selected as the best solution. The study also involved identifying areas of the new station most exposed to wear phenomena. A new transfer point was implemented in the quarry and resolved the problem of blockages.


1989 ◽  
Vol 111 (4) ◽  
pp. 400-407 ◽  
Author(s):  
M. J. Morris ◽  
J. C. Dutton

The results of an experimental investigation into the flowfield characteristics of butterfly valves under compressible flow operating conditions are reported. The experimental results include Schlieren and surface flow visualizations and flowfield static pressure distributions. Two valve disk shapes have been studied in a planar, two-dimensional test section: a generic biconvex circular arc profile and the midplane cross-section of a prototype butterfly valve. The valve disk angle and operating pressure ratio have also been varied in these experiments. The results demonstrate that under certain conditions of operation the butterfly valve flowfield can be extremely complex with oblique shock waves, expansion fans, and regions of flow separation and reattachment. In addition, the sensitivity of the valve disk surface pressure distributions to the local geometry near the leading and trailing edges and the relation of the aerodynamic torque to flow separation and reattachment on the disk are shown.


Author(s):  
Graeme G. King ◽  
Satish Kumar

Masdar is developing several carbon capture projects from power plants, smelters, steel works, industrial facilities and oil and gas processing plants in Abu Dhabi in a phased series of projects. Captured CO2 will be transported in a new national CO2 pipeline network with a nominal capacity of 20×106 T/y to oil reservoirs where it will be injected for reservoir management and sequestration. Design of the pipeline network considered three primary factors in the selection of wall thickness and toughness, (a) steady and transient operating conditions, (b) prevention of longitudinal ductile fractures and (c) optimization of total project owning and operating costs. The paper explains how the three factors affect wall thickness and toughness. It sets out code requirements that must be satisfied when choosing wall thickness and gives details of how to calculate toughness to prevent propagation of long ductile fracture in CO2 pipelines. It then uses cost optimization to resolve contention between the different requirements and arrive at a safe and economical pipeline design. The design work selected a design pressure of 24.5 MPa, well above the critical point for CO2 and much higher than is normally seen in conventional oil and gas pipelines. Despite its high operating pressure, the proposed network will be one of the safest pipeline systems in the world today.


2021 ◽  
Author(s):  
Sujet Phodapol ◽  
Tachadol Suthisomboon ◽  
Pong Kosanunt ◽  
Ravipas Vongasemjit ◽  
Petch Janbanjong ◽  
...  

Abstract Passive and active hybrid pipeline inspection gauges (PIGs) have been used for in-pipe inspection. While a passive PIG cannot control its speed, the hybrid version can achieve this by using an integrated valve specifically designed and embedded in the PIG. This study proposes a generic new method for speed adaptation in PIGs (called MC-PIG) by introducing a generic, modular, controllable, external valve unit add-on for attaching to existing conventional (passive) PIGs with minimal change. The MC-PIG method is based on the principle of morphological computation with closed-loop control. It is achieved by regulating/computing the PIG's morphology (i.e., a modular rotary valve unit add-on) to control bypass flow. Adjustment of the valve angle can affect the flow rate passing through the PIG, resulting in speed regulation ability. We use numerical simulation with computational fluid dynamics (CFD) to investigate and analyze the speed of a simulated PIG with the valve unit adjusted by proportional-integral (PI) control under various in-pipe pressure conditions. Our simulation experiments are performed under different operating conditions in three pipe sizes (16″, 18″, and 22″ in diameter) to manifest the speed adaptation of the PIG with the modular valve unit add-on and PI control. Our results show that the PIG can effectively perform real-time adaptation (i.e., adjusting its valve angle) to maintain the desired speed. The valve design can be adjusted from 5 degrees (closed valve, resulting in high moving speed) to a maximum of 45 degrees (fully open valve, resulting in low moving speed). The speed of the PIG can be regulated from 0.59 m/s to 3.88 m/s in a 16″ pipe at 4.38 m/s (in-pipe fluid velocity), 2500 kPa (operating pressure), and 62 °C (operating temperature). Finally, the MC-PIG method is validated using a 3D-printed prototype in a 6″ pipe. Through the investigation, we observed that two factors influence speed adaptation; the pressure drop coefficient and friction of the PIG and pipeline. In conclusion, the results from the simulation and prototype show close characteristics with an acceptable error.


Author(s):  
Ruoxin Li ◽  
Qing Xiao ◽  
Lijun Li ◽  
Hao Liu

In this work, we numerically studied the steady swimming of a pufferfish driven by the undulating motion of its dorsal, anal and caudal fins. The simulations are based on experimentally measured kinematics. To model the self-propelled fish swimming, a Computational Fluid Dynamics (CFD) tool was coupled with a Multi-Body-Dynamics (MBD) technique. It is widely accepted that deformable/flexible or undulating fins are better than rigid fins in terms of propulsion efficiency. To elucidate the underlying mechanism, we established an undulating fins model based on the kinematics of live fish, and conducted a simulation under the same operating conditions as rigid fins. The results presented here agree with this view by showing that the contribution of undulating fins to propulsion efficiency is significantly larger than that of rigid fins.


1999 ◽  
Vol 121 (12) ◽  
pp. 62-64 ◽  
Author(s):  
Peggy Chalmers

This article focuses on the fact that using computational fluid dynamics (CFD) and design of experiments (DOE) software, researchers are in pursuit of aircraft fluidics thrust control without moving component parts. Fluidics’ performance is dictated by complex interactions among approximately two dozen geometric and fluid properties. These complex interactions probably proved overwhelming to early researchers seeking a stable, reliable rocket flight control system. A major advantage of DOE is that it allows all the parameters to vary simultaneously. A single permutation, on the other hand, varies one parameter at a time and cannot deal with interactions among the fixed parameters. There is still more development work to be done, but indications are that CFD and DOE are leading Lockheed Martin to a promising design. Physical testing reinforces the belief that a fluidic nozzle can achieve the performance levels required. The technology that never got off the ground in the early rocket era may find itself flying high in the next generation of high-performance tactical aircraft.


Author(s):  
Nicholas J. Venero ◽  
Tim J. M. Bond ◽  
Raymond N. Burke ◽  
David J. Miles

A new technology for external rehabilitation of pipelines, known as XHab™, has been developed. This method involves wrapping multiple layers of ultra-high strength steel (UHSS) strip in a helical form continuously over an extended length of pipeline using a dedicated forming and wrapping machine. The reinforcement afforded by the strip can be used to bring a defective section of pipe (e.g. externally corroded or dented) back to its original allowable operating conditions, or even to increase the allowable operating pressure if the desired operating conditions exceed the original pipeline design limits. This paper describes the design, manufacture and testing process for a self-propelled wrapping machine for in-field rehabilitation. The wrapping apparatus consists of several major components including an opening sufficiently wide to receive the pipe, a movement assembly, a winding head, a preforming device, an accumulator and an oscillating adhesive applicator. The wrapping apparatus uses the winding head to wrap the reinforcing steel strip around the pipe. The movement assembly uses a pair of tracks in contact with the pipe to drive the wrapping apparatus along which enables helical wrapping of the reinforcing strip material. The oscillating adhesive assembly applies structural adhesive to the pipe immediately before the strip is wound. The winding head, motive assembly and adhesive applicator are electronically synchronized to one another to enable precise control of pitch and adhesive volume. The paper also describes the field application of XHab including mobilization/demobilization of equipment and interaction with other rehabilitation equipment, as well as specific aspects such as initiation and termination of wrapping, protection of rehabilitated area and implementation of cathodic protection.


Author(s):  
Susane R. Gomes ◽  
Leopoldo J. Rocco

This research aims to provide a methodology for the project of labscale hybrid motors. This development began with the thermal analysis of the fuel grain using the Flynn, Wall and Ozawa method, generating simulation entry data to maximize the motor performance. The simulation was performed with the Chemical Equilibrium Specific Impulse Code. Based on the optimum oxidizer to fuel ratio, the literature was used to supply the mathematical background to calculate the motor geometrical parameters whose operating conditions were determined throughout the simulation. Finally, firing tests were conducted to verify the reliability of the project methodology. The firing tests were performed with three injectors: two swirling and one axial. The tests showed that the higher the operating pressure the more suitable is the project, meaning the methodology developed works best in hybrid rocket motors with high operating pressures. Additionally, it was shown that the swirling flow injectors produce higher efficiency.


2018 ◽  
Vol 67 ◽  
pp. 02022
Author(s):  
Achmad Anggawirya Alimin ◽  
Bambang Heru Susanto

The increase in global aviation fuel demand has prompted ICAO to declare neutral carbon growth policy in 2050 by using bio based aviation fuel. The purpose of this study was to simulate the production of non-edible vegetable oil into bioavtur and obtain the most potential nonedible vegetable oil based on yield and conversion to be converted into bioavtur. Three potential sources to be converted into bioavtur are kosambi oil, nyamplung oil and kemiri sunan oil. This research was done by simulating of the hydroprocessing process with process simulator by varying the operating conditions on each raw material. Hydrotreating process was varied at 1-5 MPa pressure and temperature 250°C-350°C. The result showed the operating pressure with the highest conversion and yield are around 4MPa. While the operating temperature with high conversion and yield are above 290°C. Nyamplung oil has overall the largest yield and conversion than other nonedible vegetable oil with average 10% greater conversion and 3,3% greater yield at 2MPa.


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