Paper 2: Accuracy in Cylinder Pressure Measurement

1965 ◽  
Vol 180 (7) ◽  
pp. 8-16
Author(s):  
W. T. Lyn ◽  
A. J. Stockwell ◽  
C. H. T. Wang
Keyword(s):  
Frequency Response ◽  
Pressure Transducer ◽  
Continuous Recording ◽  
Cylinder Pressure ◽  
Pressure Transducers ◽  
Shock Chamber ◽  
Magnetic Type ◽  
Definition Of ◽  
Engine Development

The paper commences with a definition of the requirements of cylinder pressure measurements for (1) general engine development work, (2) frequency spectrum analysis in engine noise investigation, and (3) thermodynamics and combustion analysis. Methods for the determination of the frequency response of cylinder pressure transducers are then treated both theoretically and experimentally. For the continuous recording type of transducer a shock chamber technique is used. For the balanced pressure type of pick-up a comparison with a continuous recording type, of known frequency response, is made. These techniques do not completely simulate engine conditions and comparisons of the two types of pressure transducers were made dynamically under engine conditions. The results showed that all the continuous recording types of pressure transducer so far tested were sensitive to transient heat transfer owing to combustion. A rig was therefore developed to simulate such conditions outside the engine. Detailed descriptions are given of examples of both types of pressure transducer as developed at C.A.V. The method of recording timing marks is presented in some detail and the advantage of the ‘closed circuit’ magnetic type of degree pick-up is described.

Development on an Acquisition and Analysis System for Indicator Diagram of Piston Engine

2013 ◽  
Vol 475-476 ◽  
pp. 268-272
Author(s):  
Jian Guo Mao ◽  
Han Quan Wang
Keyword(s):  
Data Acquisition System ◽  
Interference Signal ◽  
Cylinder Pressure ◽  
Piston Engine ◽  
Indicator Diagram ◽  
Potential Value ◽  
Hardware Component ◽  
Analysis System ◽  
Engine Development

An acquisition and analysis system for indicator diagram (ID) of piston engine is developed for monitoring the cylinder pressure in engine development. The hardware component of the data acquisition system is introduced. The method of the determination of the TDC, the method of filtering the interference signal of ID and the method of implementation with Visual C++ are presented. The system can provide ID online through the experiment on Honda 125 engine. It can directly and conveniently display the information about combustion. Therefore it has a high potential value in engineering applications.

A technique for measuring frequency response of pressure, volume, and flow transducers

1979 ◽  
Vol 47 (2) ◽  
pp. 462-467 ◽  
Author(s):  
A. C. Jackson ◽  
A. Vinegar
Keyword(s):  
Frequency Response ◽  
Pressure Transducer ◽  
Test System ◽  
Good Frequency ◽  
Pressure Transducers ◽  
Response Characteristics ◽  
Measuring Frequency

A device and methodology is presented for testing the frequency response of pressure, volume, or flow transducers. Also reported are responses of selected transducers of all three types over the range of 2--120 Hz. Several pressure transducers tested had good frequency response when connected to the test system with a minimum of interconnecting fittings; others did not. Use of additional connectors degraded the response as did the addition of air-filled catheters. The frequency response of the pneumotachometers tested were influenced largely by the response characteristics of the associated pressure transducer and interconnecting fittings. These results emphasize the need to test the response characteristics of any transducer with specific connectors and fittings that are to be used to make the actual measurements of pressure, volume, or flow.

A Study of Bulk Modulus, Entrained Air, and Dynamic Pressure Measurements in Liquids

2016 ◽  
Vol 138 (10) ◽  
Author(s):  
Adam M. Hurst ◽  
Joe VanDeWeert
Keyword(s):  
Bulk Modulus ◽  
Frequency Response ◽  
Measurement System ◽  
Pressure Transducer ◽  
Dynamic Pressure ◽  
Pressure Measurements ◽  
Liquid Media ◽  
Pressure Transducers ◽  
Dynamic Pressure Measurements ◽  
Dissolved Air

Accurate static and dynamic pressure measurements in liquids, such as fuel, oil, and hydraulic fluid, are critical to the control and health monitoring of turbomachinery and aerospace systems. This work presents a theoretical and experimental study of the frequency response of pressure transducers and pressure measurement systems in liquid media. First, we theoretically predict the frequency response of pressure transducers based upon a lumped-parameter model. We then present a liquid-based dynamic pressure calibration test apparatus that validates this model by performing several critical measurements. This system first uses a vibrating liquid column to dynamically calibrate and experimentally determine the frequency response of a test pressure transducer, measurement system or geometry. Second, this calibration system experimentally extracts the bulk modulus of the fluid and the percent of entrained and/or dissolved air by volume. Bulk modulus is determined by measuring the speed of sound within the liquid and through static pressure loading while measuring the deflection of the liquid column. Bulk modulus and the entrained/dissolved gas content within the liquid greatly impact the observed frequency response of a pressure transducer or geometry. Gases, such as air, mixed or dissolved into a fluid can add substantial damping to the dynamic response of the fluid measurement system, which makes measurement of the bulk modulus and entrained and/or dissolved air critical for accurate measurement of the frequency response of a system when operating with a liquid media. All experimental results are compared to theoretical predictions.

State Failure and the Political Violence Phenomenon: A Comparative Analysis of Iraq and Syria Cases

2016 ◽  
Vol 4 (2) ◽  
pp. 170 ◽  
Author(s):  
K. Eylem Özkaya Lassalle
Keyword(s):  
Cold War ◽  
Political Violence ◽  
State Failure ◽  
The Political ◽  
Collective Violence ◽  
Short Run ◽  
Definition Of ◽  
The Cold War

The concept of failed state came to the fore with the end of the Cold War, the collapse of the USSR and the disintegration of Yugoslavia. Political violence is central in these discussions on the definition of the concept or the determination of its dimensions (indicators). Specifically, the level of political violence, the type of political violence and intensity of political violence has been broached in the literature. An effective classification of political violence can lead us to a better understanding of state failure phenomenon. By using Tilly’s classification of collective violence which is based on extent of coordination among violent actors and salience of short-run damage, the role played by political violence in state failure can be understood clearly. In order to do this, two recent cases, Iraq and Syria will be examined.

DEFINITION OF TIME SPENT ON REPAIR OF BUS TRANSMISSION UNITS TAKING INTO ACCOUNT TECHNOLOGICAL EQUIPMENT RELIABILITY

2020 ◽  
Vol 2020 (9) ◽  
pp. 29-33
Author(s):  
Sergey Bulatov
Keyword(s):  
Negative Impact ◽  
Probabilistic Method ◽  
Technological Equipment ◽  
Quality And Safety ◽  
Transmission Unit ◽  
Equipment Reliability ◽  
Hours Of Work ◽  
Definition Of ◽  
Time Decrease

The paper purpose is the effectiveness estimation in the technological equipment use, taking into account its reliability and productivity for defective transmission units of buses. The problem consists in the determination of time to be spent on repair of bus transmission units taking into account technological equipment reliability. In the paper there is used a probabilistic method for the prediction bus transmission units, and also a method of the dynamics of averages which allow ensuring minimum of costs for units downtime during repair and equipment cost. The need for repair of transmission units (gear box) arises on an average after 650 hours, the average productivity of the bench makes 4.2 bus / hour. The bench fails on the average after 4600 hours of work, the average time of the bench makes 2 hours. In such a way the solution of the problem specified allows analyzing the necessity of time decrease for transmission unit repair to avoid long downtimes of buses in repair areas without negative impact upon high repair quality and safety during the further operation.

Tests of jackhammers (formation of bench techniques)

2020 ◽  
pp. 28-32
Author(s):  
V.S. Vanaev
Keyword(s):  
Impact Energy ◽  
Bench Tests ◽  
Measuring Complex ◽  
Energy Indicators ◽  
Definition Of ◽  
Determination Of Parameters ◽  
Dynamic Indicators

Development of complex determination of parameters of jackhammers at bench tests is studied. The modern support of tests of jackhammers for the purpose of definition of their energy, vibration and noise indicators is considered. Descriptions of the SORP universal bench and UIPU measuring complex are given. Keywords jackhammer, bench, tests, processing object, energy indicators, impact energy, dynamic indicators [email protected]

Actual issues of valuation of businesses of the economic entity

2017 ◽  
Vol 31 (2) ◽  
pp. 156-162 ◽  
Author(s):  
O. V. Schneider
Keyword(s):  
Discount Rate ◽  
Accurate Prediction ◽  
Economic Activities ◽  
Business Valuation ◽  
Economic Entity ◽  
The World ◽  
Definition Of

The article summarizes the main approaches in the definition of business valuation the economic entity. In the process of business valuation, taking into account the risks of financial and economic activities necessary to obtain information on what stage the owner implements the business will receive income. The most difficult task is the impossibility of accurate prediction in determining the level of income and the determination of a discount rate capitalization of future incomes due to the instability of the economy, both in the country and around the world.

scholarly journals Betweenness centrality for temporal multiplexes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Silvia Zaoli ◽  
Piero Mazzarisi ◽  
Fabrizio Lillo
Keyword(s):  
Information Flow ◽  
Real World ◽  
Betweenness Centrality ◽  
Temporal Structure ◽  
Shortest Paths ◽  
Single Layer ◽  
Distance Metric ◽  
Definition Of

AbstractBetweenness centrality quantifies the importance of a vertex for the information flow in a network. The standard betweenness centrality applies to static single-layer networks, but many real world networks are both dynamic and made of several layers. We propose a definition of betweenness centrality for temporal multiplexes. This definition accounts for the topological and temporal structure and for the duration of paths in the determination of the shortest paths. We propose an algorithm to compute the new metric using a mapping to a static graph. We apply the metric to a dataset of $$\sim 20$$ ∼ 20 k European flights and compare the results with those obtained with static or single-layer metrics. The differences in the airports rankings highlight the importance of considering the temporal multiplex structure and an appropriate distance metric.

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