Simulation of Fuel Droplet Gasification in SI Engines

1984 ◽  
Vol 106 (4) ◽  
pp. 849-853 ◽  
Author(s):  
X. Q. Liu ◽  
C. H. Wang ◽  
C. K. Law
Keyword(s):  
Upper Bounds ◽  
Fuel Droplet ◽  
Gas Temperature ◽  
Lower And Upper Bounds ◽  
Si Engine ◽  
Initial Size ◽  
Compression Stroke ◽  
Gasification Rate ◽  
Si Engines ◽  
Temperature And Pressure

The heating and gasification of a fuel droplet during the intake and compression strokes of an SI engine are modeled. Results show that the simultaneous increases in the gas temperature and pressure during compression tend to have compensatory effects on the droplet gasification rate such that it remains somewhat insensitive to changes in the cylinder environment. Generalized results are presented allowing for the assessment of the lower and upper bounds in the initial size of the droplet that can achieve complete gasification prior to the end of the compression stroke.

A Theoretical Investigation On the Performance and Combustion Parameters in an SI Engine Fueled with Different Shale Gas Mixtures

2020 ◽  
Author(s):  
HABIB GÜRBÜZ ◽  
Serife KÖSE
Keyword(s):  
Shale Gas ◽  
Engine Performance ◽  
Good Alternative ◽  
Combustion Efficiency ◽  
Experimental Results ◽  
Combustion Model ◽  
Si Engine ◽  
Combustion Duration ◽  
Si Engines ◽  
Temperature And Pressure

Abstract In this paper, a theoretical analysis of in-cylinder combustion and indicated engine parameters by using a zero-dimensional, single-zone combustion model presented, in a SI engine operated with shale gas-1(86% CH4, 14% C2H6), shale gas-2 (81% CH4, 10% C2H6, 9% N2), shale gas-3 (58% CH4, 20% C2H6, 12% C3H8, 10% CO2), methane and LPG (30% C3H8, 70% C4H10). The technical characteristics and experimental results (i.e. engine speed, throttle position, intake air temperature and pressure, combustion duration and combustion efficiency) of a single-cylinder SI engine operated with LPG was processed for developing of theoretical combustion model. Also, the results of the theoretical combustion model by LPG fuel and the experimental results by LPG operated SI engine are compared and provided to the validation of the theoretical model. The results showed that the shale gas-1 has the potential to be a good alternative fuel for SI engines soon with an average engine performance of 6.4% lower than LPG in the range of ?=0.83-1.2. Also, methane has an average engine performance of 8.5% lower than LPG. However, shale gas-2 and shale gas-3 caused an average 21% decline at the engine performance.

Extension of the Spatial PDI Model to Three Dimensions

1997 ◽  
Vol 84 (1) ◽  
pp. 176-178
Author(s):  
Frank O'Brien
Keyword(s):  
Population Density ◽  
Dimensional Space ◽  
Finite Lattice ◽  
Three Dimensional ◽  
Upper Bounds ◽  
Three Dimensions ◽  
Lower And Upper Bounds ◽  
Density Index ◽  
Three Dimensional Space

The author's population density index ( PDI) model is extended to three-dimensional distributions. A derived formula is presented that allows for the calculation of the lower and upper bounds of density in three-dimensional space for any finite lattice.

Energy of spherical fuzzy graphs

2020 ◽  
pp. 321-332
Author(s):  
S. Yahya Mohamed ◽  
A. Mohamed Ali
Keyword(s):  
Adjacency Matrix ◽  
Upper Bounds ◽  
Fuzzy Graph ◽  
Lower And Upper Bounds ◽  
Fuzzy Graphs

In this paper, the notion of energy extended to spherical fuzzy graph. The adjacency matrix of a spherical fuzzy graph is defined and we compute the energy of a spherical fuzzy graph as the sum of absolute values of eigenvalues of the adjacency matrix of the spherical fuzzy graph. Also, the lower and upper bounds for the energy of spherical fuzzy graphs are obtained.

scholarly journals Relationship between Age and Value of Information for a Noisy Ornstein–Uhlenbeck Process

Entropy ◽  
2021 ◽  
Vol 23 (8) ◽  
pp. 940
Author(s):  
Zijing Wang ◽  
Mihai-Alin Badiu ◽  
Justin P. Coon
Keyword(s):  
Value Of Information ◽  
Markov Models ◽  
Upper Bounds ◽  
Distribution Functions ◽  
Lower And Upper Bounds ◽  
Uhlenbeck Process ◽  
Source Data ◽  
Non Linear ◽  
Queue Model ◽  
Selection Of

The age of information (AoI) has been widely used to quantify the information freshness in real-time status update systems. As the AoI is independent of the inherent property of the source data and the context, we introduce a mutual information-based value of information (VoI) framework for hidden Markov models. In this paper, we investigate the VoI and its relationship to the AoI for a noisy Ornstein–Uhlenbeck (OU) process. We explore the effects of correlation and noise on their relationship, and find logarithmic, exponential and linear dependencies between the two in three different regimes. This gives the formal justification for the selection of non-linear AoI functions previously reported in other works. Moreover, we study the statistical properties of the VoI in the example of a queue model, deriving its distribution functions and moments. The lower and upper bounds of the average VoI are also analysed, which can be used for the design and optimisation of freshness-aware networks. Numerical results are presented and further show that, compared with the traditional linear age and some basic non-linear age functions, the proposed VoI framework is more general and suitable for various contexts.

The Lower and Upper Bounds of Turán Number for Odd Wheels

2021 ◽  
Vol 37 (3) ◽  
pp. 919-932
Author(s):  
Byeong Moon Kim ◽  
Byung Chul Song ◽  
Woonjae Hwang
Keyword(s):  
Upper Bounds ◽  
Lower And Upper Bounds ◽  
Turán Number

scholarly journals Lower and upper bounds of quantum battery power in multiple central spin systems

2021 ◽  
Vol 103 (5) ◽  
Author(s):  
Li Peng ◽  
Wen-Bin He ◽  
Stefano Chesi ◽  
Hai-Qing Lin ◽  
Xi-Wen Guan
Keyword(s):  
Upper Bounds ◽  
Spin Systems ◽  
Lower And Upper Bounds ◽  
Battery Power

Third Hankel determinants for two classes of analytic functions with real coefficients

2021 ◽  
Vol 33 (4) ◽  
pp. 973-986
Author(s):  
Young Jae Sim ◽  
Paweł Zaprawa
Keyword(s):  
Analytic Functions ◽  
Univalent Functions ◽  
Upper Bounds ◽  
Hankel Determinant ◽  
Lower And Upper Bounds ◽  
Hankel Determinants ◽  
The Third ◽  
Typically Real ◽  
Class Of Functions ◽  
Typically Real Functions

Abstract In recent years, the problem of estimating Hankel determinants has attracted the attention of many mathematicians. Their research have been focused mainly on deriving the bounds of H 2 , 2 {H_{2,2}} or H 3 , 1 {H_{3,1}} over different subclasses of 𝒮 {\mathcal{S}} . Only in a few papers third Hankel determinants for non-univalent functions were considered. In this paper, we consider two classes of analytic functions with real coefficients. The first one is the class 𝒯 {\mathcal{T}} of typically real functions. The second object of our interest is 𝒦 ℝ ⁢ ( i ) {\mathcal{K}_{\mathbb{R}}(i)} , the class of functions with real coefficients which are convex in the direction of the imaginary axis. In both classes, we find lower and upper bounds of the third Hankel determinant. The results are sharp.

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