Influence of the Exhaust System on Performance of a 4-Cylinder Supercharged Engine

1998 ◽  
Vol 120 (4) ◽  
pp. 855-860 ◽  
Author(s):  
F. Trenc ◽  
F. Bizjan ◽  
A. Hribernik
Keyword(s):  
Pressure Pulse ◽  
Exhaust System ◽  
Medium Size ◽  
Advantages And Disadvantages ◽  
Available Energy ◽  
Good Utilization ◽  
The Individual ◽  
Radial Turbines ◽  
Manifold System ◽  
Four Cylinders

Twin entry radial turbines are mostly used to drive compressors of small and medium size 6-cylinder diesel engines where the available energy of the undisturbed exhaust pulses can be efficiently used to drive the turbine of a turbocharger. Three selected cylinders feed two separated manifold branches and two turbine inlets and prevent negative interaction of pressure waves and its influence on the scavenging process of the individual cylinders. In the case of a four-stroke, 4-cylinder engine, two selected cylinders, directed by the firing order, can be connected to one (of the two) separated manifold branches that feeds one turbine entry. Good utilization of the pressure pulse energy, together with typically longer periods of reduced exhaust flow can lead to good overall efficiency of the “two-pulse” system. Sometimes this system can be superior to the single manifold system with four cylinders connected to one singleentry turbine. The paper describes advantages and disadvantages of the above described exhaust systems applied to a turbocharged and aftercooled 4-cylinder Diesel engine. Comparisons supported by the analyses of the numerical and experimental results are also given in the presented paper.

Influence of the Exhaust System Design on Scavenging Characteristic and Emissions of a Four-Cylinder Supercharged Engine

2000 ◽  
Vol 122 (4) ◽  
pp. 556-561
Author(s):  
Ferdinand Trenc ◽  
Francˇisˇek Bizjan ◽  
Brane Sˇirok ◽  
Alesˇ Hribernik
Keyword(s):  
Gas Exchange ◽  
Pressure Pulse ◽  
Exhaust System ◽  
Exhaust Gas ◽  
Good Utilization ◽  
System A ◽  
Different Types ◽  
Valve Overlap ◽  
Exhaust Gas Emissions ◽  
Fresh Charge

A four-stroke four-cylinder turbocharged engine can be fitted with two different types exhaust system: a simple common manifold fed by all cylinders, or a twin-branch manifold, where two selected cylinders, directed by the firing order, feed two separate turbine entries. In this case good utilization of the exhaust pressure pulse energy can be achieved at higher loads and lower engine speeds, leading to good overall turbocharger efficiency and favorable pressure distribution during the gas-exchange period. Improved engine scavenging capability affects quality and quantity of the fresh charge and consequently influences the exhaust gas emissions. If, in addition, valve overlap period is increased the benefit of this system is still more evident. Common manifold exhaust system shows its advantage through lower pumping losses at higher engine speeds and lower loads. Both systems were optimized and the results of numerical and experimental work are presented in the paper. [S0742-4795(00)00404-X]

scholarly journals Design and Performance Analysis of B15 Engine Intake System

2018 ◽  
Vol 1 (1) ◽  
pp. 1
Author(s):  
Shirong Wen ◽  
Baolei Wei ◽  
Huabei Tong
Keyword(s):  
Automobile Industry ◽  
Exhaust System ◽  
Helmholtz Resonator ◽  
Design Flow ◽  
Intake Manifold ◽  
One Dimensional ◽  
Intake System ◽  
Advantages And Disadvantages ◽  
Target Value ◽  
The Individual

<p>In recent years, with the development of the economy, the automobile industry has also undergone ever-changing changes. At present, the design of the engine in addition to the car to achieve the dynamic, economic indicators but also need to meet their emissions and noise requirements, it is necessary for the engine into the exhaust system for in-depth study. The intake system mainly comprises two parts of the pipeline and the intake manifold before the intake manifold, in which the pipeline in front of the manifold acts to reduce the intake noise. How to design the components of the intake system reasonably and analyze its comprehensive performance is the most important topic in the project.</p><p>Firstly, this article introduces the principle of variable valve timing and variable intake manifold technology, establishes B15 engine model in GT-Power software and uses the test data to complete the calibration of the model so that the error is not more than 5% for subsequent simulation calculations. In order to design the silencer element of the intake system, the sensitivity of the parameters of the Helmholtz resonator, 1/4 wavelength tube and air filter is calculated and analyzed, and the influence of the parameter change on the muffler performance is summarized. The design flow and method of the intake muffler element are described in detail, and the concrete design scheme is put forward. The noise of the muffler element is optimized according to the problem that the noise of the individual order is higher than the target value. After the optimization of the intake system air intake noise improved significantly, the pressure loss is no higher than 2.5 kPa, in line with the target value requirements, the optimization effect is good.</p><p>Secondly, in order to analyze the performance of the intake manifold, three methods are proposed: the zero-dimensional or one-dimensional model is used to simplify the processing, and the CFD software is used to calculate the steady-state or isolated transients and the coupling analysis using one-dimensional and three-dimensional software. By comparing the advantages and disadvantages of the three methods, it is found that the coupling of software can obtain real-time boundary condition in the calculation process and have high accuracy. This paper focuses on the key issues that need to be solved by coupling with GT-Power and STAR-CCM + software and completes the calculation of the model.</p><p>Finally, in order to evaluate the advantages and disadvantages of the intake muffler element better, the maximum noise of the intake system is calculated by using the model of the vehicle acceleration in the GT-Power software, and the maximum noise of the intake system is 61.8 dB (A) which satisfies the target requirement for the individual contribution rate through noise.</p>

Multidisciplinary management of vascular access for haemodialysis: from the preparation of the initial access to the treatment of stenosis and thrombosis

VASA ◽  
2011 ◽  
Vol 40 (3) ◽  
pp. 188-198 ◽  
Author(s):  
Reinhold ◽  
Haage ◽  
Hollenbeck ◽  
Mickley ◽  
Ranft
Keyword(s):  
Vascular Access ◽  
Central Venous ◽  
Advantages And Disadvantages ◽  
Multidisciplinary Study ◽  
First Results ◽  
Lower Complication ◽  
Lower Complication Rate ◽  
Access Problems ◽  
Arteriovenous Grafts ◽  
The Individual

In February 2008 a multidisciplinary study group was established in Germany to improve the treatment of patients with potential vascular access problems. As one of the first results of their work interdisciplinary recommendations for the management of vascular access were provided, from the creation of the initial access to the treatment of complications. As a rule the wrist arteriovenous fistula (AVF) is the access of choice due to its lower complication rate when compared to other types of access. The AVF should be created 3 months prior to the expected start of haemodialysis to allow for sufficient maturation. Second and third choice accesses are arteriovenous grafts (AVG) and central venous catheters (CVC). Ultrasound is a reliable tool for vessel selection before access creation, and also for the diagnosis of complications in AVF and grafts. Access stenosis and thrombosis can be treated surgically and interventionally. The comparison of both methods reveals advantages and disadvantages for each. The therapeutic decision should be based on the individual patients’ constitution, and also on the availability and experience of the involved specialists.

ADMINISTRATION MODELS IN THE SYSTEM OF FORENSIC EXAMINATION INSTITUTIONS FROM THE POSITION OF SCIENTIFIC MANAGEMENT

2016 ◽  
Vol 16 ◽  
pp. 179-184
Author(s):  
S. V. Kudryashova
Keyword(s):  
Scientific Management ◽  
Competing Values ◽  
State Institutions ◽  
Advantages And Disadvantages ◽  
Forensic Examination ◽  
Forensic Institutions ◽  
The Individual

The individual forensic activity in comparison with the activity of forensic experts of specialized state institutions is considered, the main advantages and disadvantages are determined. The directions of development of specialized state and non-state forensic institutions are presented in accordance with R. Quinn's competing values model.

Wykorzystanie mediów społecznościowych w komunikacji z klientem na przykładzie firm sektora piwowarskiego

2015 ◽  
pp. 161-176 ◽  
Author(s):  
Piotr Szamrowski ◽  
Adam Pawlewicz
Keyword(s):  
Social Media ◽  
Public Relations ◽  
Small Enterprises ◽  
Brewing Industry ◽  
Video Sharing ◽  
Advantages And Disadvantages ◽  
Media Platform ◽  
The Individual ◽  
Media Channels ◽  
Regional Character

The main objective of this paper is to identify the platforms and social media tools utilized by the brewing industry in communication with the stakeholders, mainly with potential clients. In addition, the study sought to determine the nature of the published content, identify those responsible for their management, and present the advantages and disadvantages of their conduct in communication and creating the image of the company. The results indicate that only 25% of the surveyed companies do not use social media in PR. This applies only to small enterprises, with regional character. All the major brewing companies in their public relations activities use at least one type of social media, focusing in most cases on social networking (Facebook) and Video Sharing (YouTube). In addition, some of the largest brands included in the individual equity groups have their own social media channels used to communicate with the stakeholders. General promotion of company products and, what is very important, creating a dialogue with social media platform community, were seen as the most important benefits of using social media.

Indices and Correlates of Positive Emotion in Psychopathology

2019 ◽  
pp. 95-118
Author(s):  
Sunny J. Dutra ◽  
Marianne Reddan ◽  
John R. Purcell ◽  
Hillary C. Devlin ◽  
Keith M. Welker
Keyword(s):  
Positive Emotion ◽  
Self Report ◽  
Individual Level ◽  
Advantages And Disadvantages ◽  
Innovative Methods ◽  
Behavioral Coding ◽  
Broad Array ◽  
Positive Valence ◽  
The Individual ◽  
Clinical Populations

This chapter not only draws from previous authoritative measurement overviews in the general field of emotion, but also advances these resources in several key ways. First, it provides a specific focus on positive valence systems, which have not yet received specific methodological attention. Second, the field of positive emotion (PE) has expanded in recent years with new and innovative methods, making an updated review of methodological tools timely. Third, the chapter incorporates discussion of PE disturbance in clinical populations and the methods best suited to capture PE dysfunctions. This chapter also outlines some tools that can allow researchers to capture a broad array of PE quantified by self-report, behavioral coding, and biological correlates as seen through changes in the central and peripheral nervous system (i.e., brain and body). After reviewing PE measurement methods and correlates, this chapter includes several methods for studying PE beyond the individual level (i.e., interpersonal) and traditional laboratory settings (i.e., ambulatory or experience sampling). It provides key examples of their applications to study PE in clinical populations while acknowledging several of their basic advantages and disadvantages.

scholarly journals Validity of the Gender Dysphoria diagnosis and incidence trends in Sweden: a nationwide register study

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Malin Indremo ◽  
Richard White ◽  
Thomas Frisell ◽  
Sven Cnattingius ◽  
Alkistis Skalkidou ◽  
...  
Keyword(s):  
Gender Dysphoria ◽  
Age Groups ◽  
Medical Intervention ◽  
Future Research ◽  
Advantages And Disadvantages ◽  
Incidence Trends ◽  
Interaction Terms ◽  
Definition Of ◽  
The Individual ◽  
Nationwide Register Study

AbstractThe aim of this study was to examine the validity of the Gender Dysphoria (GD) diagnoses in the Swedish National Patient Register (NPR), to discuss different register-based definitions of GD and to investigate incidence trends. We collected data on all individuals with registered GD diagnoses between 2001 and 2016 as well as data on the coverage in the NPR. We regarded gender confirming medical intervention (GCMI) as one proxy for a clinically valid diagnosis and calculated the positive predictive value (PPV) for receiving GCMI for increasing number of registered GD diagnoses. We assessed crude and coverage-adjusted time trends of GD during 2004–2015 with a Poisson regression, using assigned sex and age as interaction terms. The PPV for receiving GCMI was 68% for ≥ 1 and 79% for ≥ 4 GD-diagnoses. The incidence of GD was on average 35% higher with the definition of ≥ 1 compared to the definition of ≥ 4 diagnoses. The incidence of GD, defined as ≥ 4 diagnoses increased significantly during the study period and mostly in the age categories 10–17 and 18–30 years, even after adjusting for register coverage. We concluded that the validity of a single ICD code denoting clinical GD in the Swedish NPR can be questioned. For future research, we propose to carefully weight the advantages and disadvantages of different register-based definitions according to the individual study’s needs, the time periods involved and the age-groups under study.

Approaches to the Organization of International Accounting in Russian Enterprises

TEM Journal ◽  
2021 ◽  
pp. 249-258
Author(s):  
Ekaterina V. Surkova ◽  
Galina A. Skachko ◽  
Larisa K. Nikandrova ◽  
Maria M. Starkova ◽  
Nina F. Sakharova
Keyword(s):  
Financial Reporting ◽  
Accounting Information ◽  
Financial Statements ◽  
Reporting Standards ◽  
Optimal Method ◽  
Accounting Standard ◽  
Financial Reporting Standards ◽  
Advantages And Disadvantages ◽  
The Individual ◽  
Selection Of

The article discusses current issues of transformation of accounting information in accordance with international financial reporting standards (IFRS). This study is primarily aimed at developing approaches that determine the need for Russian enterprises to provide accounting information comparable at the international level. The authors analyze methods of transferring data from the Russian Accounting Standard (RAS) to IFRS. The methods used to form financial statements in accordance with IFRS are discussed. The issues of the application of these methods, as well as their advantages and disadvantages, are discussed. The author's approach to the selection of the optimal method of transformation is proposed taking into account the individual needs of organizations.

scholarly journals Proposal of the Functional System for the Airline Companies Financial Situation Assessment

2019 ◽  
Vol 21 (1) ◽  
pp. 3-8
Author(s):  
Ondrej Stopka ◽  
Ladislav Bartuska ◽  
Jacek Caban ◽  
Larisa M. Kapustina
Keyword(s):  
Economic Performance ◽  
General Procedure ◽  
Functional System ◽  
Aviation Industry ◽  
Financial Indicators ◽  
Financial Health ◽  
Financial Situation ◽  
Advantages And Disadvantages ◽  
The Individual

This paper presents the draft methodology to be applied for evaluating the financial health of airlines. In the introductory part, specific attributes, regarding the individual types of airlines, are described. Subsequent parts of the manuscript outline advantages and disadvantages to measure airlines performance when implementing financial indicators, as well as a general procedure to evaluate the financial situation of a company operating in the aviation industry. The most important part of the paper includes the proposal of the specific functional system to evaluate the economic performance of airlines. Financial evaluation itself (evaluation of financial indicators of the enterprise‘s economic performance) is performed through a particular case study when comparing several existing airlines.

scholarly journals Legal and Economic Reglamentation Aspects of Individual Enterprise Functioning

Ekonomika ◽  
2008 ◽  
Vol 81 ◽  
Author(s):  
Dalia Perkumienė ◽  
Vida Čiulevičienė
Keyword(s):  
Legal Entity ◽  
Advantages And Disadvantages ◽  
Individual Enterprise ◽  
Before And After ◽  
The Individual

The operation of individual enterprises established in Lithuania was regulated by various separate laws which caused much inconvenience. Therefore, the Lithuanian law on individual enterprises entered into force on 1 January 2004. The article aims to present the outstanding peculiarities of an individual enterprise as a legal entity which could be considered as advantages and disadvantages. The article considers the individual enterprise before and after the entry into force of the Lithuanian law on individual enterprises.

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