Active Air Control System Development Using Charge Air Integrated Manifold Engine Numerical Simulation (CAIMENS)

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
Diana K. Grauer ◽  
Kirby S. Chapman ◽  
Ali Keshavarz
Keyword(s):  
Numerical Simulation ◽  
Pressure Drop ◽  
Pressure Wave ◽  
Peak Pressure ◽  
System Development ◽  
Intake Manifold ◽  
Before And After ◽  
Mass Fractions ◽  
Pulsation Model ◽  
The Impact

This paper reports on an investigation into the transient, compressible flow physics that impact the trapped equivalence ratio. A comprehensive, variable geometry, multicylinder turbocharger-reciprocating engine computer simulation (T-RECS) has been developed to illustrate the effect of airflow imbalance on an engine. A new model, the charge air integrated manifold engine numerical simulation (CAIMENS), is a manifold flow model coupled with the T-RECS engine processor that uses an integrated set of fundamental principles to determine the crank angle-resolved pressure, temperature, burned and unburned mass fractions, and gas exchange rates for the cylinder. CAIMENS has the ability to show the transient impact of one cylinder firing on each successive cylinder. The pulsation model also describes the impact of manifold pressure drop on in-cylinder peak pressure and the pressure wave introduced to the intake manifold by uncovering the intake ports. CAIMENS provides the information necessary to quantify the impact of airflow imbalance, and allows for the visualization of the engine system before and after airflow correction. The model shows that not only does the manifold pressure drop have a significant impact on the in-cylinder peak pressure but it also has an impact on the pressure wave introduced to the intake manifold as the ports are opened. Also, each cylinder has a considerable impact on the airflow into each successive cylinder.

Active Air Control System Development Using Charge Air Integrated Manifold Engine Numerical Simulation (CAIMENS)

2007 ◽  
Author(s):  
Diana K. Grauer ◽  
Kirby S. Chapman ◽  
Ali Keshavar
Keyword(s):  
Numerical Simulation ◽  
Pressure Drop ◽  
Flow Rate ◽  
Pressure Wave ◽  
Equivalence Ratio ◽  
Peak Pressure ◽  
Intake Manifold ◽  
Airflow Rate ◽  
Engine System ◽  
The Impact

The natural gas transmission industry integrates turbochargers into the engine system to strategically increase airflow for the purpose of decreasing pollutant emissions, such as Nitrogen Oxide (NOX). Regulations are expected to be tightened in the coming years, forcing transmission companies to look past turbochargers for compliance. The solution to further decreasing emissions lies not in further retrofit, but focusing on the physics of the current system. The flow rate physics of the intake and exhaust manifolds impede equal distribution of air from the turbocharger to each cylinder. Imbalance in airflow creates a discontinuity in the trapped equivalence ratio from cylinder to cylinder. The trapped equivalence ratio is directly proportional to NOX production and a function of the fuel flow rate, airflow rate, and, in two-stroke cycle engines, the scavenging efficiency. Only when these three characteristics are balanced cylinder to cylinder will the combustion and the NOX production in each cylinder be equal. The engine NOX production will be disproportionately high if even one cylinder operates less lean relative to the other cylinders. Balancing the NOX production between cylinders can lower the overall NOX production of the engine. This paper reports on an investigation into the transient, compressible flow physics that impact the trapped equivalence ratio. A comprehensive, variable geometry, multi-cylinder Turbocharger-Reciprocating Engine Computer Simulation (T-RECS) has been developed to illustrate the effect of airflow imbalance on an engine. A new model, the Charge Air Integrated Manifold Engine Numerical Simulation (CAIMENS), is a manifold flow model coupled with the T-RECS engine processor that uses an integrated set of fundamental principles to determine the crank angle-resolved pressure, temperature, burned and unburned mass fractions, and gas exchange rates for the cylinder. CAIMENS has the ability to show the transient impact of one cylinder firing on each successive cylinder. The pulsation model also describes the impact of manifold pressure drop on in-cylinder peak pressure and the pressure wave introduced to the intake manifold by uncovering the intake ports. CAIMENS provides the information necessary to quantify the impact of airflow imbalance, and allows for the visualization of the engine system before and after airflow correction. The model shows that not only does the manifold pressure drop have a significant impact on the in-cylinder peak pressure, but it also has an impact on the pressure wave introduced to the intake manifold as the ports are opened. Also, each cylinder has a considerable impact on the airflow into each successive cylinder.

scholarly journals Numerical Simulation of Borehole Parameters for Coal Seam Gas Pre-Drainage

2021 ◽  
Vol 39 (4) ◽  
pp. 1328-1334
Author(s):  
Xiaoyan Li ◽  
Jiyu Zheng ◽  
Jinpin Liu
Keyword(s):  
Numerical Simulation ◽  
Pressure Drop ◽  
Gas Pressure ◽  
Borehole Diameter ◽  
Gas Drainage ◽  
Drainage Time ◽  
Drainage Radius ◽  
Simulation Results ◽  
The Impact ◽  
The Relationship

Borehole parameters are quite important for gas drainage. This paper studies the impact of borehole diameter and time on gas drainage and performs numerical simulation on the distribution of gas pressure under the conditions of different borehole diameters and drainage times. The simulation results reveal that, as the borehole diameter increases, the gas drainage volume increases along with it and the gas pressure decreases, but such effect on gas drainage is limited. In terms of drainage time, the longer the drainage time, the greater the drainage impact scope. Taking a gas pressure drop of 51% as the indicator of the effective pre-drainage radius, the distance from the point with a gas pressure drop of 51% to the position of the borehole is the effective pre-drainage radius. When the pre-drainage reached the 30th, 45th, 60th, 75th, and 90th day, the effective pre-drainage radius was 1.04m, 1.29m, 1.51m, 1.68m, and 1.82m respectively. According to the numerical simulation results, the effective pre-drainage radius varies with the pre-drainage time, and the fitting analysis of the two indicates that the relationship between the two can be described by a power function.

Characterization of the Pressure Wave Emitted From Implosion of Submerged Cylindrical Shell Structures

2012 ◽  
Author(s):  
Michael D. Shields ◽  
Pawel Woelke ◽  
Najib N. Abboud
Keyword(s):  
Pressure Wave ◽  
Pressure Pulse ◽  
Peak Pressure ◽  
Structural Parameters ◽  
Shell Structures ◽  
High Fidelity ◽  
Pressure Waves ◽  
Structural Configurations ◽  
The Impact

Buckling of submerged cylindrical shells is a sudden and rapid implosion which emits a high pressure pulse that may be damaging to nearby structures. The characteristics of this pressure pulse are dictated by various parameters defining the shell structure such as the length to diameter ratio, shell thickness, material, and the existence and configuration of internal stiffeners. This study examines, through the use of high fidelity coupled fluid-structure finite element computations, the impact of various structural parameters on the resulting pressure wave emanating from the implosion. The results demonstrate that certain structural configurations produce pressure waves with higher peak pressure and impulse thereby enhancing the potential for damage to nearby structures.

scholarly journals A numerical study to improve the position and angle of the producer gas injector inside the intake manifold to minimize emissions and efficiency enhancement of a bi engine

2021 ◽  
pp. 100-109
Author(s):  
Hussein A. Mahmood ◽  
Ali O. Al-Sulttani ◽  
Osam H. Attia ◽  
Nor Mariah. Adam
Keyword(s):  
Numerical Simulation ◽  
Numerical Study ◽  
Single Point ◽  
Flow Characteristics ◽  
Engine Performance ◽  
Simulation Software ◽  
Petrol Engine ◽  
Intake Manifold ◽  
Producer Gas ◽  
The Impact

To develop a petrol engine so that it works under the bi-engine pattern (producer gas-petrol) without any additional engine modifications, a single-point injection method inside the intake manifold is a simple and inexpensive method. Still, it leads to poor mixing performance between the air and producer gas. This deficiency can cause unsatisfactory engine performance and high exhaust emissions. In order to improve the mixing inside the intake manifold, nine separate cases were modelled to evaluate the impact of the position and angle orientation inside the intake manifold on the uniformity and spread of the mixture under AFR=2.07. A petrol engine (1.6 L), the maximum engine speed (8000 rpm), and bi-engine mode (petrol-producer gas engine). The employ of the numerical simulation software (ANSYS workbench 19), the propagation, flow characteristics, and uniformity of the blend within the nine different cases were evaluated. According to the outcomes of the numerical simulation, it was found that creating vortices and turbulent flow for the producer gas and air inside the intake manifold is the perfect method to obtain a uniformity mixture of air and producer gas inside the intake manifold. In addition, extending the blending duration allows air and producer gas fuel to be mixed efficiently. Furthermore, the greatest uniformity and the maximum spread rate at the outlet of manifold are obtained in cases 1, 4, and 7, when the producer gas injector location is constant (P1, P2 or P3). In addition, the weakest spread of producer gas at the outlet of the manifold is observed in case 9 in comparison with the other cases. Moreover, it is observed that case (1) generated the maximum uniformity index (UI) level

scholarly journals A Numerical Simulation Of Severe Cyclone Sidr-2007

2013 ◽  
Vol 32 ◽  
pp. 43-54
Author(s):  
Nikhil Chandra Sarkar ◽  
Anowarul Islam ◽  
Sujit Kumar Debsarma
Keyword(s):  
Numerical Simulation ◽  
Pressure Drop ◽  
Natural Disasters ◽  
Tropical Cyclones ◽  
Time Dependent ◽  
Coastal Zones ◽  
Cyclone Sidr ◽  
Reported Data ◽  
The Impact ◽  
Good Agreement

The most severe tropical cyclones are formed over the Bay of Bengal because of its complex geometric structure and shallow coastal bathymetry. These natural disasters significantly impact our lives as well as the environment. To quantify the impact of such disasters, we analyzed data pertaining to the severe cyclone Sidr-2007, considering the cyclone’s duration and angle of land fall, as well as the bathymetry of the near-coastal zones. We propose a reliable hydrodynamic model to simulate the severity of such cyclones. The model’s reliability is verified by comparison of the numerical results with actual storm-surge data. Our model requires meteorological and hydrological inputs, including the time-dependent positions of the storm centre, the maximum wind radius, as well as pressure-drop and bathymetry data. The model results are in good agreement with the reported data. DOI: http://dx.doi.org/10.3329/ganit.v32i0.13645 GANIT J. Bangladesh Math. Soc. (ISSN 1606-3694) 32 (2012) 43-54  

scholarly journals Flyer acceleration experiments using a KrF laser system with a long pulse duration and pressure and thickness of isobaric zone induced in impacted materials

2001 ◽  
Vol 19 (4) ◽  
pp. 623-630 ◽  
Author(s):  
T. KADONO ◽  
M. YOSHIDA ◽  
N.K. MITANI ◽  
T. MATSUMURA ◽  
E. TAKAHASHI ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Pulse Duration ◽  
Transit Time ◽  
Peak Pressure ◽  
Laser System ◽  
Diamond Plate ◽  
Krf Laser ◽  
Long Pulse ◽  
The Impact ◽  
Initial Peak

Flyer acceleration experiments are carried out using a KrF laser system with a pulse duration of 10–15 ns and an intensity of ∼1.0 × 1013 W/cm2. Three-layered targets (aluminum–polyimide–tantalum) are used. First, an average velocity of laser-driven tantalum flyers with a thickness of 4 and 8 μm is estimated. Then, in a collision of a flyer with a copper layer attached to a diamond plate, we measure a transit time of a shock wave in the diamond. The impact velocity is estimated based on the transit time and a numerical simulation. This numerical simulation also shows that the initial peak pressure caused by the impact of a 4-μm-thick flyer is kept at 11 Mbar for 12–13 μm in thickness. Finally, whether this thickness is enough for EOS measurements is discussed.

Strategic Role of Zakat in Multidimensional Quality of Life in Sijunjung, Indonesia

2018 ◽  
Vol 15 (1) ◽  
pp. 55-72
Author(s):  
Herlin Hamimi ◽  
Abdul Ghafar Ismail ◽  
Muhammad Hasbi Zaenal
Keyword(s):  
Quality Of Life ◽  
Positive Impact ◽  
Wealth Distribution ◽  
Absolute Poverty ◽  
Before And After ◽  
The Status ◽  
Being There ◽  
The Impact

Zakat is one of the five pillars of Islam which has a function of faith, social and economic functions. Muslims who can pay zakat are required to give at least 2.5 per cent of their wealth. The problem of poverty prevalent in disadvantaged regions because of the difficulty of access to information and communication led to a gap that is so high in wealth and resources. The instrument of zakat provides a paradigm in the achievement of equitable wealth distribution and healthy circulation. Zakat potentially offers a better life and improves the quality of human being. There is a human quality improvement not only in economic terms but also in spiritual terms such as improving religiousity. This study aims to examine the role of zakat to alleviate humanitarian issues in disadvantaged regions such as Sijunjung, one of zakat beneficiaries and impoverished areas in Indonesia. The researcher attempted a Cibest method to capture the impact of zakat beneficiaries before and after becoming a member of Zakat Community Development (ZCD) Program in material and spiritual value. The overall analysis shows that zakat has a positive impact on disadvantaged regions development and enhance the quality of life of the community. There is an improvement in the average of mustahik household incomes after becoming a member of ZCD Program. Cibest model demonstrates that material, spiritual, and absolute poverty index decreased by 10, 5, and 6 per cent. Meanwhile, the welfare index is increased by 21 per cent. These findings have significant implications for developing the quality of life in disadvantaged regions in Sijunjung. Therefore, zakat is one of the instruments to change the status of disadvantaged areas to be equivalent to other areas.

ANALISIS PENGARUH PEMBANGUNAN JALAN LAYANG JANTI TERHADAP PERKEMBANGAN TATA RUANG KAWASAN JANTI STUDI KASUS : KAWASAN JANTI, DESA CATURTUNGGAL, KABUPATEN SLEMAN, D. I. YOGYAKARTA

2017 ◽  
Vol 11 (3) ◽  
pp. 255
Author(s):  
Jeky El Boru
Keyword(s):  
Road Network ◽  
Open Space ◽  
Qualitative Description ◽  
Analysis Method ◽  
Open Spaces ◽  
The Road ◽  
Before And After ◽  
Linkage Method ◽  
The Impact ◽  
Parking Place

Abstract: This research aims to analyze the impact of Janti Flyover Construction toward the growth of layout at Janti Urban Area, including structured space, open space, and linkage. Method used for data collecting are observation, air photograph monitoring, and interview, whereas the analysis method is qualitative description, which is the superimposed method of two layers, that are the layout condition before and after flyover construction. The result shows that the impact of Janti Flyover construction can be seen on building mass (solid), the increasing number of open spaces, including the road network, parking place, and park, whereas the relation between spaces, visually and structurally, can be seen on the growth of buildings which have new shapes and styles, therefore the performance of the overall building does not have a proportional shape. Considering Janti Street at the collective relation, its role is getting stronger as the main frame road network.Keywords: Flyover construction, layout changing, Janti AreaAbstrak: Penelitian ini bertujuan untuk menganalisis pengaruh pembangunan Jalan Layang Janti terhadap perkembangan tata ruang Kawasan Janti, meliputi ruang terbangun, ruang terbuka, serta hubungan antar ruang (“linkage”). Metode pengumpulan data dilakukan melalui observasi, pengamatan foto udara, dan wawancara; sedangkan metode analisis melalui deskripsi secara kualitatif yang berupa “superimposed method” dari dua lapisan kondisi lahan, yakni kondisi tata ruang sebelum dan sesudah pembangunan jalan layang. Hasil penelitian menunjukkan bahwa pengaruh pembangunan Jalan Layang Janti terdapat pada massa bangunan (“solid”), pertambahan ruang terbuka yang berupa jaringan jalan, parkir, dan taman; sedangkan pada hubungan antar ruang ̶ secara visual dan struktural ̶ yakni tumbuhnya bangunan dengan bentuk dan gaya baru, sehingga bentuk tampilan bangunan secara keseluruhan tidak proporsional. Pada hubungan kolektif, Jalan Janti semakin kuat perannya sebagai kerangka utama jaringan jalan.Kata kunci : Pembangunan jalan layang, tata ruang, Kawasan Janti

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