scholarly journals Gas System for the ATLAS NSW Micromegas Detectors: Design Aspects and Advanced Validation Methods for their QA/QC

2019 ◽  
Vol 24 ◽  
pp. 23 ◽  
Author(s):  
T. Alexopoulos ◽  
E. Gazis ◽  
S. Maltezos ◽  
A. Antoniou ◽  
V. Gika ◽  
...  
Keyword(s):  
Distribution System ◽  
Gas Flow ◽  
Test Methods ◽  
Gas Leak ◽  
Gas System ◽  
Medical Needles ◽  
Flow Pressure ◽  
Loss Method ◽  
Lock In ◽  
Rate Loss

In this work we present the design aspects of the Gas Distribution System of NSW Micromegas detectors, simulation results and gas flow / pressure uniformity. We also describe the appropriate gas leak test methods, a conventional and an alternative one, being used in the Quality Assurance and Quality Control of the detectors. For the performance studies we used emulated leak branches based on medical needles. We also describe proposed upgrade stages combining the proposed competitive Flow Rate Loss method with the Lock-in Amplifier technique. Further, we describe the baseline setup for the Gas Tightness Station at BB5/CERN.

scholarly journals The gas flow pattern through small size Resistive Plate Chambers with 2 mm gap

2021 ◽  
Vol 16 (11) ◽  
pp. P11022
Author(s):  
Y. Pezeshkian ◽  
A. Kiyoumarsioskouei ◽  
M. Ahmadpouri ◽  
G. Ghorbani
Keyword(s):  
Gas Flow ◽  
Fluid Dynamic ◽  
Gas Flow Rate ◽  
Argon Gas ◽  
Dynamic Methods ◽  
Gas System ◽  
Gas Molecules ◽  
Simulation Results ◽  
Resistive Plate Chambers ◽  
The Difference

Abstract A prototype of a single-gap glass Resistive Plate Chamber (RPC) is constructed by the authors. To find the requirements for better operation of the detector's gas system, we have simulated the flow of the Argon gas through the detector by using computational fluid dynamic methods. Simulations show that the pressure inside the chamber linearly depends on the gas flow rate and the chamber's output hose length. The simulation results were compatible with experiments. We have found that the pressure-driven speed of the gas molecules is two orders of magnitude larger in the inlet and outlet regions than the blocked corners of a 14 × 14 cm2 chamber, and most likely the difference in speed is higher for larger detectors and different geometries.

Reverse Flow Pressure Limiting Aperture

2000 ◽  
Vol 6 (1) ◽  
pp. 21-30 ◽  
Author(s):  
Gerasimos D. Danilatos
Keyword(s):  
Pressure Difference ◽  
Gas Flow ◽  
Reverse Flow ◽  
Gas Jet ◽  
The Third ◽  
The Core ◽  
Annular Aperture ◽  
Flow Through ◽  
Flow Pressure ◽  
Gas Molecules

The reverse flow pressure limiting aperture is a device that creates and sustains a substantial gas pressure difference between two chambers connected via an aperture. The aperture is surrounded by an annular orifice leading to a third chamber. The third chamber is maintained at a relatively high pressure that forces gas to flow through the annular aperture into the first of said two chambers. The ensuing gas flow develops into a supersonic annular gas jet, the core of which is coaxial with the central aperture. A pumping action is created at the core of the jet and any gas molecules leaking through the aperture from the second chamber are entrained and forced into the first chamber, thus creating a substantial pressure difference between the first and second chamber.

Modelling of Sonic Jets for Gas Leak Applications

2019 ◽  
Author(s):  
Stefano Minotti ◽  
Alessandro Corsini ◽  
Giovanni Delibra ◽  
Gabriele Lucherini ◽  
Stefano Rossin ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Ventilation System ◽  
Supersonic Jet ◽  
Cfd Simulations ◽  
Fuel Gas ◽  
Safety Issues ◽  
Gas Leakage ◽  
Round Jets ◽  
Gas Leak ◽  
Gas System

Abstract Design of gas turbine packages is subjected to safety issues and the related guidelines are provided by ISO-21789. According to this code, the ventilation system shall guarantee a good and safe dilution in case of an unexpected gas leakage from components of the fuel gas system inside the enclosure. The evaluation of the dilution is commonly carried out by CFD simulations and the ISO-21789 indicates the criteria to evaluate the danger of a gas leak by estimating the cloud volume of the explosive mixture. To follow this prescription and to properly calculate the exact volume cloud, it is fundamental to accurately reproduce the fuel gas leak, which is always a supersonic jet of fuel gas into an air-ventilated domain. The main criticality is to simulate a supersonic jet into a complex domain such as the gas turbine package, considering the industrial goals in terms of accuracy and time constraints. The complexity is due to the geometry of the package and to the multiple locations where the leakage could occur. In such context, it is preferable to develop an advanced modeling of the phenomenon rather than simply improve the detail of the CFD, that could turn out to be unfeasible for industrial goals. For this reason, the authors present a series of simulations of under-expanded jets at high pressure ratios carried out to investigate the applicability of the sonic source approach to not-round jets.

Cement Plug Sealing Studies of Silica Cement Systems

2019 ◽  
Author(s):  
Anisa Noor Corina ◽  
Nils van der Tuuk Opedal ◽  
Torbjørn Vrålstad ◽  
Sigbjørn Sangesland
Keyword(s):  
Gas Flow ◽  
Curing Temperature ◽  
Small Scale ◽  
The Past ◽  
Laboratory Setup ◽  
Gas Leak ◽  
Zonal Isolation ◽  
Cement Mixture ◽  
Cement Plug

Abstract A cement plug is widely applied for permanent abandonment phase to provide long-term zonal isolation against fluid flow. Maintaining cement plug integrity is a challenging task, and loss in cement sealing poses risks to the surrounding environment and surface safety. It is well-known that the cement performance is affected by cement material and downhole conditions. Nevertheless, investigations linking these influencing factors with the sealing of cement plugs are still limited, especially with the lack of proper equipment in the past. In the present work, a small-scale laboratory setup has been constructed to test the sealing ability of a cement plug. It has unique features that can simulate plugging operations at the downhole conditions and preserve the cement curing condition. By testing using this setup, it is possible to measure the minimum differential pressure required for gas to flow across the cement plug and the gas leak rate. The silica cement mixture was selected as the plug material, prepared using silica flour. Investigation of silica cement under the influence of expanding agent additive and various curing temperature was carried out. It was found that adding an expanding agent improved the sealing of cement plugs. Moreover, samples cured at a high temperature were less resistant to gas flow with the leak path observed at the cement/steel interface, indicating debonding.

scholarly journals Prototype of LPG gas leakage detector using flame sensor and MQ-2 sensor

2020 ◽  
Vol 1 (1) ◽  
pp. 32-38
Author(s):  
Harya Gusdevi ◽  
Ade Setya P ◽  
Puji Handini Zulaeha
Keyword(s):  
Mobile Phone ◽  
Side Effect ◽  
Gas Flow ◽  
Solenoid Valve ◽  
The Public ◽  
Gas Leakage ◽  
Gas Leak ◽  
Unpleasant Odor ◽  
The Republic ◽  
Gas Cylinders

The conversion of kerosene use in household to gas, in addition to the decision of the Republic of Indonesia minister in relation to the movement of kerosene to gas, gas also given an affordable price, how to use it more effectively. But the public is also expected to be careful about how to use it, because the gas is explosive and leaking causing unpleasant odor (gas leak) even a more dangerous side effect is the explosion of gas cylinders. To evercome these problems then need a tool that can detect gas leakage, in order to prevent gas leakage early. Therefore the authors designed a device that can detect gas leakage by using Sensor Mq-2 and will issue sound gas alarm warning leak by Modul ISD 1760, and will stop the gas flow from the tube to the stove using a Solenoid Valve. There is also a Flame Sensor’s hardware to detect a fire if there is a spark emerging and spraying water into spots that are likely to spark fire. All hardware will be in if using ATMega 328microcontroller.Monitoring can use android smartphone, with the application that can send a warning to the mobile phone.

scholarly journals Perbandingan hidrograf banjir menggunakan beberapa metode perhitungan curah hujan efektif (studi kasus: Das Cisadane Hulu)

2015 ◽  
Vol 12 (2) ◽  
pp. 187-198
Author(s):  
Orita Mega Delani ◽  
Bambang Dwi Dasanto
Keyword(s):  
Peak Discharge ◽  
Effective Rainfall ◽  
Hydrologic Modelling ◽  
Run Off ◽  
Constant Rate ◽  
Loss Method ◽  
Dominant Characteristic ◽  
Rate Loss ◽  
Method Model ◽  
Scs Cn

Calculation of effective rainfall is an important step in hydrologic modelling. The used methods to calculate effective rainfall rarely observe watershed conditions on site. The objectives of the study is to determine the optimum method in calculating effective rainfall based on infiltration approach in Upper Cisadane Watershed and to analysis dominant characteristic of watershed on selected method. SCS-CN, Initial and Constant Rate Loss Method, and Green and Ampt Loss Method were the methods that used to estimate run off value in Upper Cisadane Watershed. The simulation was performed using HEC-HMS and tested using EF and RMSE on peak discharge and volume of hydrograph. The three events of peak discharge was chosen. Based on EF and RMSE test, Green and Ampt Loss Method model showed that simulated hydrograph was similar to measured hydrograph in Upper Cisadane Watershed with EF was 0.764 and RMSE was 5.93 m3/s. Based on the analysis, green and Ampt method is recommended to use on watershed with mountainous topographic and simillar on shape with Upper Cisadane Watershed.

scholarly journals Prototype of LPG Gas Leakage Detector Using Flame Sensor and MQ-2 Sensor

2020 ◽  
Vol 5 (1) ◽  
pp. 28-36
Author(s):  
Harya Gusdevi ◽  
Ade Setya ◽  
Puji Handini Zulaeha
Keyword(s):  
Mobile Phone ◽  
Side Effect ◽  
Gas Flow ◽  
Solenoid Valve ◽  
The Public ◽  
Gas Leakage ◽  
Gas Leak ◽  
Unpleasant Odor ◽  
The Republic ◽  
Gas Cylinders

The conversion of kerosene use in household to gas, in addition to the decision of the Republic of Indonesia minister in relation to the movement of kerosene to gas, gas also given an affordable price, how to use it more effectively. But the public is also expected to be careful about how to use it, be-cause the gas is explosive and leaking causing unpleasant odor (gas leak) even a more dangerous side effect is the explosion of gas cylinders. To evercome these problems then need a tool that can detect gas leakage, in order to prevent gas leakage early. Therefore the authors designed a device that can detect gas leakage by using Sensor Mq-2 and will issue sound gas alarm warning leak by Modul ISD 1760, and will stop the gas flow from the tube to the stove using a Solenoid Valve. There is also a Flame Sensor’s hardware to detect a fire if there is a spark emerging and spraying water into spots that are likely to spark fire. All hardware will be in if using ATMega 328microcontroller.Monitoring can use android smartphone, with the application that can send a warning to the mobile phone 

An Investigation on Mechanism of Droplet Generation in High Inertial Gaseous Flow

2019 ◽  
Author(s):  
Xinyu Yao ◽  
Zhenyu Liu ◽  
Huiying Wu
Keyword(s):  
Gas Flow ◽  
Channel Wall ◽  
Droplet Generation ◽  
Generation Process ◽  
Visualization Experiment ◽  
Gas System ◽  
Inertial Flow ◽  
Detachment Time ◽  
Water Gas ◽  
Droplet Detachment

Abstract Droplet generation involving high inertial gas flow in a T-junction microchannel was experimentally and numerically studied in this work. The effect of high inertial flow on the water droplet generation was investigated based on the obtained results. At various gas Reynold (Re) numbers and liquid Capillary (Ca) numbers, the unique flow regime mapping including squeezing, dripping and jetting was observed. It was found that stable aqueous droplets are generated in the squeezing and dripping flow regimes. Visualization experiment shows that the morphology of droplets generated in the water-gas system is different from that in the traditional water-oil system. As the Re number increases or the Ca number decreases, the droplet length decreases. Increasing both Re number and Ca number can increase the detachment frequency. Based on the 3D VOF simulations, the droplet attachment to one of the channel wall during the pinch-off period and the rebound of liquid phase after droplet detachment was observed. Droplet size, detachment time and droplet generation frequency were then analyzed for the droplet generation. The dominant detachment mechanism during the whole droplet generation process was also discussed in this work.

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