Numerical Modeling of Munitions Liquid Agent With Solid Heel in the Metal Parts Furnace

2010 ◽  
Author(s):  
Yunhan Zheng ◽  
Alfred Webster ◽  
Mike Vanoni
Keyword(s):  
Numerical Model ◽  
Operating Efficiency ◽  
Chemical Agent ◽  
Vaporization Rate ◽  
Processing Conditions ◽  
Metal Parts ◽  
Chemical Agents ◽  
Computational Fluid Dynamics Cfd ◽  
Liquid Chemical ◽  
Fill Level

The Metal Parts Furnace (MPF) is a custom-designed incinerator and has been successfully demonstrated for treatment of munitions containing chemical agents since the first full-scale prototype baseline incineration facility on Johnston Island in 1990. The development of a numerical model to predict peak vaporization rate and total vaporization time during processing can provide the ability to control operating parameters to minimize the potential for any upset conditions such as agent overload, and to ensure that appropriate processing conditions are chosen to achieve desired safety factors. The numerical model will also provide the capability to maximize operating efficiency and to help adjust conditions during processing of different agents and munitions configurations. The Continental Research and Engineering (CR&E) Peak Vaporization Rate (PVR) model was initially developed in 1988 for the MPF to provide munitions tray vaporization rates as a function of the MPF temperature and munitions fill level. The model was updated and calibrated to test data in 1994. The calibrated PVR model is suitable for munitions with varying quantities of liquid chemical agent; however, this model can only be used to predict the vaporization rate of the liquid chemical agent. In order to simulate the effect of the solidified agent found in the munitions, CR&E has developed a Computational Fluid Dynamics (CFD) model based the vaporization rate model to simulate heating, melting, and vaporization of liquid chemical agent mixed with a varying solid heel mass fraction.

Single Cell Based Microelectrode Array Biosensors

2003 ◽  
Vol 773 ◽  
Author(s):  
Mo Yang ◽  
Shalini Prasad ◽  
Xuan Zhang ◽  
Mihrimah Ozkan ◽  
Cengiz S. Ozkan
Keyword(s):  
Electrical Activity ◽  
Single Cell ◽  
Cellular Response ◽  
Microelectrode Array ◽  
Fast Fourier Transformation ◽  
Chemical Agent ◽  
Extracellular Potential ◽  
Membrane Excitability ◽  
Specific Chemical ◽  
Chemical Agents

AbstractExtracellular potential is an important parameter which indicates the electrical activity of live cells. Membrane excitability in osteoblasts plays a key role in modulating the electrical activity in the presence of chemical agents. The complexity of cell signal makes interpretation of the cellular response to a chemical agent very difficult. By analyzing shifts in the signal power spectrum, it is possible to determine a frequency spectrum also known as Signature Pattern Vectors (SPV) specific to a chemical. It is also essential to characterize single cell sensitivity and response time for specific chemical agents for developing detect-to-warn biosensors. We used a 4x4 multiple Pt microelectrode array to spatially position single osteoblast cells, by using a gradient AC field. Fast Fourier Transformation (FFT) and Wavelet Transformation (WT) analyses were used to extract information pertaining to the frequency of firing from the extracellular potential.

Transfer of Drugs and Other Chemicals Into Human Milk

PEDIATRICS ◽  
1989 ◽  
Vol 84 (5) ◽  
pp. 924-936
Author(s):  
Keyword(s):  
Drug Therapy ◽  
Human Milk ◽  
Breast Feeding ◽  
Drug Exposure ◽  
Chemical Agent ◽  
Blood Concentrations ◽  
Lactating Women ◽  
Chemical Agents ◽  
New Information ◽  
Oral Analgesia

Since the first publication of this statement, much new information has been published concerning the transfer of drugs and chemicals into human milk. This information, in addition to other research published before 1983, makes a revision of the previous statement necessary. In this revision, lists of the pharmacologic or chemical agents transferred into human milk and their possible effects on the infant or on lactation, if known, are provided (Tables 1 to 7). The fact that a pharmacologic or chemical agent does not appear in the Tables is not meant to imply that it is not transferred into human milk or that it does not have an effect on the infant but indicates that there are no reports in the literature. These tables should assist the physician in counseling a nursing mother regarding breast-feeding when the mother has a condition for which a drug is medically indicated. The following questions should be considered when prescribing drug therapy to lactating women. (1) Is the drug therapy really necessary? Consultation between the pediatrician and the mother's physician can be most useful. (2) Use the safest drug; for example, acetaminophen rather than aspirin for oral analgesia. (3) If there is a possibility that a drug may present a risk to the infant (eg, phenytoin, phenobarbital), consideration should be given to measurement of blood concentrations in the nursing infant. (4) Drug exposure to the nursing infant may be minimized by having the mother take the medication just after completing a breast-feeding and/or just before the infant has his or her lengthy sleep periods.

Numerical Simulation of Insulin Depot Formation and Absorption in Subcutaneous Tissue Modeled as a Homogeneous Anisotropic Porous Media

2021 ◽  
Author(s):  
Michael Zedelmair ◽  
Abhijit Mukherjee
Keyword(s):  
Porous Media ◽  
Numerical Model ◽  
Insulin Pump ◽  
Subcutaneous Tissue ◽  
Saturated Porous Media ◽  
Anisotropic Porous Media ◽  
Effective Option ◽  
Computational Fluid Dynamics Cfd ◽  
Experimental Findings ◽  
Subcutaneous Adipose

Abstract In this study, a numerical model of the insulin depot formation and absorption in the subcutaneous adipose tissue is developed using the commercial Computational Fluid Dynamics (CFD) software. A better understanding of these mechanisms can be helpful in the development of new devices and cannula geometries as well as predicting the concentration of insulin in the blood. The injection method considered in this simulation is by the use of an insulin pump using a rapid acting U100 insulin analogue. The depot formation is analyzed running Bolus injections ranging from 5-15 units of insulin corresponding to 50-150µl. The insulin is injected into the subcutaneous tissue in the abdominal region. The tissue is modeled as a fluid saturated porous media. An anisotropic approach to define the tissue permeability is studied by varying the value of the porosity in parallel and perpendicular direction having an impact on the viscous resistance to the flow. Following recent experimental findings this configuration results in a disk shaped insulin depot. To be able to run the simulation over longer timeframes the depot formation model has been extended implementing the process of absorption of insulin from the depot. The developed model is then used to analyze the formation of the insulin depot in the tissue when using different flow rates and cannula geometries. The numerical model is an effective option to evaluate new cannula designs prior to the manufacturing and testing of prototypes, which are rather time consuming and expensive.

scholarly journals A Coupled, Semi-Numerical Model for Thermal Analysis of Medium Frequency Transformer

Energies ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 328 ◽  
Author(s):  
Haonan Tian ◽  
Zhongbao Wei ◽  
Sriram Vaisambhayana ◽  
Madasamy Thevar ◽  
Anshuman Tripathi ◽  
...  
Keyword(s):  
Numerical Model ◽  
Analytical Model ◽  
Electromagnetic Analysis ◽  
Medium Frequency ◽  
Fluid Analysis ◽  
Fluid Behavior ◽  
Proposed Model ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method ◽  
Thermal Fluid Analysis

Medium-frequency (MF) transformer has gained much popularity in power conversion systems. Temperature control is a paramount concern, as the unexpected high temperature declines the safety and life expectancy of transformer. The scrutiny of losses and thermal-fluid behavior are thereby critical for the design of MF transformers. This paper proposes a coupled, semi-numerical model for electromagnetic and thermal-fluid analysis of MF oil natural air natural (ONAN) transformer. An analytical model that is based on spatial distribution of flux density and AC factor is exploited to calculate the system losses, while the thermal-hydraulic behavior is modelled numerically leveraging the computational fluid dynamics (CFD) method. A close-loop iterative framework is formulated by coupling the analytical model-based electromagnetic analysis and CFD-based thermal-fluid analysis to address the temperature dependence. Experiments are performed on two transformer prototypes with different conductor types and physical geometries for validation purpose. Results suggest that the proposed model can accurately model the AC effects, losses, and the temperature rises at different system components. The proposed model is computationally more efficient than the full numerical method but it reserves accurate thermal-hydraulic characterization, thus it is promising for engineering utilization.

scholarly journals Numerical and Experimental Investigation on a Moonpool-Buoy Wave Energy Converter

Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2364 ◽  
Author(s):  
Hengxu Liu ◽  
Feng Yan ◽  
Fengmei Jing ◽  
Jingtao Ao ◽  
Zhaoliang Han ◽  
...  
Keyword(s):  
Numerical Model ◽  
Wave Energy ◽  
Wave Energy Converter ◽  
Scale Model ◽  
Energy Converter ◽  
Point Absorber ◽  
Motion Responses ◽  
Computational Fluid Dynamics Cfd ◽  
The Time Domain ◽  
Good Agreement

This paper introduces a new point-absorber wave energy converter (WEC) with a moonpool buoy—the moonpool platform wave energy converter (MPWEC). The MPWEC structure includes a cylinder buoy and a moonpool buoy and a Power Take-off (PTO) system, where the relative movement between the cylindrical buoy and the moonpool buoy is exploited by the PTO system to generate energy. A 1:10 scale model was physically tested to validate the numerical model and further prove the feasibility of the proposed system. The motion responses of and the power absorbed by the MPWEC studied in the wave tank experiments were also numerically analyzed, with a potential approach in the frequency domain, and a computational fluid dynamics (CFD) code in the time domain. The good agreement between the experimental and the numerical results showed that the present numerical model is accurate enough, and therefore considering only the heave degree of freedom is acceptable to estimate the motion responses and power absorption. The study shows that the MPWEC optimum power extractions is realized over a range of wave frequencies between 1.7 and 2.5 rad/s.

Study of Selectively Permeable Coatings to Textiles

2011 ◽  
Vol 1312 ◽  
Author(s):  
Joseph G. Sargent ◽  
Jun S. Lee ◽  
Emmanuelle Reynaud ◽  
Michael D. Gilbert ◽  
James M. Sloan
Keyword(s):  
Electron Microscopy ◽  
Industrial Applications ◽  
Chemical Agent ◽  
Coating Materials ◽  
Water Permeation ◽  
Chemical Agents ◽  
Transmission Electron ◽  
Coated Fabric ◽  
Coating Uniformity ◽  
Electron Microscopy Analysis

ABSTRACTBreathable barrier textiles for both chemical agent and moisture are being actively developed for military and industrial applications. An ideal approach is to coat textiles with a semi-permeable film that allows the transport of water while still serving as a barrier for chemical agents. Sulfonated poly (styrene-block-isobutylene-block-styrene) (SIBS) copolymer spontaneously phase separates upon drying from solution to produce a nanostructured film with the controlled barrier functionality for water permeation and repelling of chemical agents.The objective of this research is to investigate coating uniformity and phase morphology of SIBS coating materials fabricated by novel solvent combinations. Scanning electron microscopy analysis is used for the assessment of the coating uniformity as well as the level of adhesion between the polymer coating and fabric substrate. Transmission electron microscopy is used to characterize the phase separation morphology of the SIBS copolymer coating. The mechanical behavior of the coated fabric is determined through tensile and shear tests and is compared to the bare fabric behavior. The goal of this study is to relate the processing conditions of the final nanostructured block copolymer coated fabric produced on industrial scale.

Numerical Investigation of Dusts Removal from Tramway Surface by Street Vacuum Sweeper

2011 ◽  
Vol 236-238 ◽  
pp. 1619-1622 ◽  
Author(s):  
Bo Fu Wu ◽  
Jin Lai Men ◽  
Jie Chen
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Numerical Model ◽  
Pressure Drop ◽  
Removal Efficiency ◽  
Pressure Drops ◽  
Operational Safety ◽  
Airflow Field ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method

In order to enhance the operational safety of tram vehicle and reduce the wear of guide wheels mounted on the vehicle, it is necessary to remove particles such as dusts and silts from tramway surface. The aim of this paper is to evaluate the effectiveness of street vacuum sweeper for sucking up dusts from tramway surface. A numerical model was developed based on dusts removal process. Under different pressure drops across the pickup head of the street vacuum sweeper, the flow field and dusts removal efficiency were analyzed with computational fluid dynamics (CFD) method. The numerical results show that a higher pressure drop can improve the airflow field in the pickup head and results in higher dusts removal efficiency, but higher pressure drop definitely need more energy. Therefore, a balance should be taken into consideration.

Numerical Investigation of the Obstacle on Hydrogen Distribution in a Vessel

2020 ◽  
Author(s):  
Tianlin Wang ◽  
Lili Tong ◽  
Xuewu Cao
Keyword(s):  
Numerical Model ◽  
Nuclear Power ◽  
Power Plants ◽  
Volume Concentration ◽  
Safety Issue ◽  
High Momentum ◽  
Hydrogen Distribution ◽  
Hydrogen Flow ◽  
Severe Accidents ◽  
Computational Fluid Dynamics Cfd

Abstract Hydrogen combustion and explosion is an important safety issue in nuclear power plants (NPPs) containment during postulated severe accidents or in utilization of hydrogen. It is significant to understand the hydrogen flow and distribution in space for mitigating hydrogen risk. In this paper, a numerical model to investigate hydrogen flow and distribution in a vessel is established using computational fluid dynamics (CFD) code GASFLOW. Hydrogen is simulated by helium which is used to study the hydrogen distribution. The k-ε turbulent model is selected to establish the numerical model, and the numerical model which has no obstacle inside the vessel or includes the obstacle inside is verified under medium momentum conditions of injected gas by comparing numerical results with experimental data. Regardless of the presence of the obstacle in the vessel, helium stratification occurs under all momentum condition of injected gas. When the obstacle is present, it blocks the flow path of the injected helium to the upper space, then the helium volume concentration in upper space is lower than the condition that there is no obstacle in the vessel. As the initial Froude number increases from 0.19 to 19.29, the flow mechanism around the obstacle under high momentum condition of injected gas is different from that under medium or low momentum conditions. Consequently, the boundary of the helium stratification moves down, and the distribution of helium looks more uniform in most area of the vessel for high momentum conditions of injected gas.

Numerical Modeling of Berm Breakwater Optimization With Varying Berm Geometry Using REEF3D

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Athul Sasikumar ◽  
Arun Kamath ◽  
Onno Musch ◽  
Hans Bihs ◽  
Øivind A. Arntsen
Keyword(s):  
Numerical Model ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Flow Through Porous Media ◽  
Cfd Model ◽  
Production Chain ◽  
Offshore Production ◽  
Physical Model Tests ◽  
Computational Fluid Dynamics Cfd ◽  
Flow Through

Harbors are important infrastructures for an offshore production chain. These harbors are protected from the actions of sea by breakwaters to ensure safe loading, unloading of vessels and also to protect the infrastructure. In current literature, research regarding the design of these structures is majorly based on physical model tests. In this study a new tool, a three-dimensional (3D) numerical model is introduced. The open-source computational fluid dynamics (CFD) model REEF3D is used to study the design of berm breakwaters. The model uses the Volume-averaged Reynolds-averaged Navier-Stokes (VRANS) equations to solve the porous flows. At first, the VRANS approach in REEF3D is validated for flow through porous media. A dam break case is simulated and comparisons are made for the free surface both inside and outside the porous medium. The numerical model REEF3D is applied to show how to extend the database obtained with purely numerical results, simulating different structural alternatives for the berm in a berm breakwater. Different simulations are conducted with varying berm geometry. The influence of the berm geometry on the pore pressure and velocities are studied. The resulting optimal berm geometry is compared to the geometry according to empirical formulations.

Performance and Losses Analysis for Radial Turbine Featuring a Multi-Channel Casing Design

2020 ◽  
Author(s):  
Ahmed Farid Hassan ◽  
Markus Schatz ◽  
Damian M. Vogt
Keyword(s):  
Internal Flow ◽  
Turbine Rotor ◽  
Control Technique ◽  
Operating Efficiency ◽  
Control Mechanisms ◽  
Turbine Performance ◽  
Performance Reduction ◽  
Partial Admission ◽  
Computational Fluid Dynamics Cfd ◽  
Opening And Closing

Abstract A novel control technique for radial turbines is under investigation for providing turbine performance controllability, especially in turbocharger applications. This technique is based on replacing the traditional spiral casing with a Multi-channel Casing (MC). The MC divides the turbine rotor inlet circumferentially into a certain number of channels. Opening and closing these channels controls the inlet area and, consequently, the turbine performance. The MC can be distinguished from other available control techniques in that it contains no movable parts or complicated control mechanisms. Within the casing, this difference makes it practical for a broader range of applications. In this investigation, a turbocharger featuring a turbine with MC has been tested on a hot gas test stand. The experimental test results show a reduction in the turbine operating efficiency when switching from full to partial admission. This reduction increases when reducing the admission percentage. To ensure the best performance of the turbine featuring MC while operating at different admission configurations, it becomes crucial to investigate its internal flow field at both full and partial admission to understand the reasons for this performance reduction. A full 3D Computational Fluid Dynamics (CFD) model of the turbine was created for this investigation. It focuses on identifying the loss mechanisms associated with partial admission. Steady and unsteady simulations were performed and validated with available test data. The simulation results show that operating the turbine at partial admission results in highly disturbed flow. It also detects the places where aerodynamic losses occur and which are responsible for this performance reduction. This operation also shows flow unsteadiness even when operating at steady conditions. This unsteadiness depends mainly on the admission configuration and percentage.

Sign in / Sign up

Export Citation Format

Share Document