scholarly journals Energetic aspect of diesel engine operation

2009 ◽  
Vol 137 (2) ◽  
pp. 84-92
Author(s):  
Jerzy GIRTLER
Keyword(s):  
Diesel Engine ◽  
Markov Process ◽  
Classical Mechanics ◽  
Original Method ◽  
The Body ◽  
Measurement Unit ◽  
Integral Calculus ◽  
Engine Operation ◽  
Semi Markov Process ◽  
Energetic Aspect

The paper provides a proposal of a quantitative interpretation of operation which (as the operation of Hamilton and Maupertius presented in classical mechanics and the operation issuing from change of the body momentum) is considered as a physical quantity with the measurement unit called a joule-second [joule × second]. An original method for analyzing and estimating the engine operation has been demonstrated in the energetic aspect for the operating needs. The homogenous Poison process and semi-Markov process have been herein applied to justify the usability of such interpreted operation. The two processes have made it possible to formulate a model deterioration of the diesel engine operation over time. Thus, the model is a random Poisson process or semi-Markov process. It has also been shown that the integral calculus can be (and should be) applied to identify the energetic properties of an engine. Considerations on the energetic aspect of diesel engine operation are provided on the example of marine engines of a ship’s main propulsion system.

scholarly journals The time of the first transition of the semi-Markov process in the evaluation of diesel engine operation

2011 ◽  
Vol 145 (2) ◽  
pp. 89-98
Author(s):  
Jacek RUDNICKI
Keyword(s):  
Diesel Engine ◽  
Markov Process ◽  
Markov Processes ◽  
Marine Diesel Engine ◽  
Engine Operation ◽  
Marine Diesel ◽  
Semi Markov Process ◽  
Deterioration Process ◽  
Semi Markov Processes ◽  
Engine Reliability

The paper presents the extension of the method discussed in the literature of quantitative evaluation of operation on the example of a marine engine. According to this interpretation, the engine operation can be shown as a physical quantity. In this aspect, based on the main marine diesel engine an evaluation of the usefulness of this index for the description of the engine reliability related properties has been performed. Apart from the generally used reliability indexes, it seems purposeful to consider the engine operation (as well as its functional subsystems) in the evaluative way, so that it could be described by both energy and time. In this aspect, in the analysis the semi-Markov processes theory was used that allowed a description of the concept of the model of the engine deterioration process as a random one. The problem of the time of the first transition of the semi-Markov process to a subset of specified classes of states representing particular technical and reliability-related states of engine was described in detail.

scholarly journals Prognosis of Cancer - A Semi Markov Process

2021 ◽  
Vol 10 (5) ◽  
pp. 146-150
Author(s):  
Manjula S Dalabanjan ◽  
Pratibha Agrawal ◽  
Deepthi T ◽  
M. D. Suranagi
Keyword(s):  
Markov Process ◽  
Malignant Tumors ◽  
Survival Function ◽  
Likelihood Estimation ◽  
Building Blocks ◽  
Absolute Number ◽  
The Body ◽  
Benign Tumors ◽  
Time Data ◽  
Semi Markov Process

Cancer begins in cells, the building blocks that make up tissues. Tissues make up the organs of the body. The buildup of extra cells often forms a mass of tissue called a growth, polyp or tumor. Tumors can be benign (non cancerous) or malignant (cancerous). Benign tumors are not as harmful as malignant tumors. The transformation of normal cells into cancer cells is called Carcinogenesis.Cancer is one of the major health problems persisting world-wide. Urbanization, industrialization, changes in lifestyles, population growth and ageing all have contributed for epidemiological transition in the country. The absolute number of new cancer cases is increasing rapidly due to growth in size of the population The stages of cancer are considered as different states of a Markov Process. Discrete-time Markov chains have been successfully used to investigate treatment programs and health care protocols for chronic diseases like HIV, AIDS, Hypertension etc. In this study, the process of carcinogenesis was classified into 6 states. The history of every patient is recorded in the form of a data segment starting from initial state.The transitional states and absorbing states are well defined. Since all the patients under study do not reach the last state at a given point of time, the process was studied as a Semi Markov Process. Maximum likelihood estimation of the transitional probabilities, the survival function, the hazard function and the waiting time distribution of patients in different states were studied. This kind of statistical methodology used to study the prognosis of cancer can be applied to real-time data of cancer patients.

DIESEL ENGINE OPERATION IN USE OF FUEL WITH ADDITIVES

2018 ◽  
pp. 18-24
Author(s):  
Petar Kazakov ◽  
Atanas Iliev ◽  
Emil Marinov
Keyword(s):  
Diesel Engine ◽  
Fuel Consumption ◽  
Diesel Fuel ◽  
Internal Combustion Engines ◽  
Experimental Studies ◽  
Combustion Engines ◽  
Engine Operation ◽  
Factors Affecting ◽  
Operating Modes ◽  
Positive Effects

Over the decades, more attention has been paid to emissions from the means of transport and the use of different fuels and combustion fuels for the operation of internal combustion engines than on fuel consumption. This, in turn, enables research into products that are said to reduce fuel consumption. The report summarizes four studies of fuel-related innovation products. The studies covered by this report are conducted with diesel fuel and usually contain diesel fuel and three additives for it. Manufacturers of additives are based on already existing studies showing a 10-30% reduction in fuel consumption. Comparative experimental studies related to the use of commercially available diesel fuel with and without the use of additives have been performed in laboratory conditions. The studies were carried out on a stationary diesel engine СМД-17КН equipped with brake КИ1368В. Repeated results were recorded, but they did not confirm the significant positive effect of additives on specific fuel consumption. In some cases, the factors affecting errors in this type of research on the effectiveness of fuel additives for commercial purposes are considered. The reasons for the positive effects of such use of additives in certain engine operating modes are also clarified.

Stabilizing Excessive EGR With an Oxidation Catalyst on a Modern Diesel Engine

2002 ◽  
Author(s):  
Ming Zheng ◽  
David K. Irick ◽  
Jeffrey Hodgson
Keyword(s):  
Diesel Engine ◽  
Oxidation Catalyst ◽  
Stable Operation ◽  
Exhaust Gas ◽  
Oxides Of Nitrogen ◽  
Engine Operation ◽  
Turbocharged Diesel Engine ◽  
New Approach ◽  
Cyclic Variations ◽  
Gas Recirculation

For diesel engines (CIDI) the excessive use of exhaust gas recirculation (EGR) can reduce in-cylinder oxides of nitrogen (NOx) generation dramatically, but engine operation can also approach zones with high instabilities, usually accompanied with high cycle-to-cycle variations and deteriorated emissions of total hydrocarbon (THC), carbon monoxide (CO), and soot. A new approach has been proposed and tested to eliminate the influences of recycled combustibles on such instabilities, by applying an oxidation catalyst in the high-pressure EGR loop of a turbocharged diesel engine. The testing was directed to identifying the thresholds of stable operation at high rates of EGR without causing cycle-to-cycle variations associated with untreated recycled combustibles. The elimination of recycled combustibles using the oxidation catalyst showed significant influences on stabilizing the cyclic variations, so that the EGR applicable limits are effectively extended. The attainability of low NOx emissions with the catalytically oxidized EGR is also evaluated.

Partially observable semi-Markov reward processes

1993 ◽  
Vol 30 (3) ◽  
pp. 548-560 ◽  
Author(s):  
Yasushi Masuda
Keyword(s):  
Markov Process ◽  
Counting Process ◽  
Probabilistic Interpretation ◽  
Real Domain ◽  
Semi Markov Process ◽  
Reward Process ◽  
Markov Reward ◽  
Partially Observable ◽  
Joint Behavior

The main objective of this paper is to investigate the conditional behavior of the multivariate reward process given the number of certain signals where the underlying system is described by a semi-Markov process and the signal is defined by a counting process. To this end, we study the joint behavior of the multivariate reward process and the multivariate counting process in detail. We derive transform results as well as the corresponding real domain expressions, thus providing clear probabilistic interpretation.

Experimental Studies on Diesel Engine with Piston Crown Modification Using an Optimum Alternative Fuel

2015 ◽  
Vol 813-814 ◽  
pp. 830-835
Author(s):  
Akkaraju H. Kiran Theja ◽  
Rayapati Subbarao
Keyword(s):  
Diesel Engine ◽  
Combustion Chamber ◽  
Experimental Studies ◽  
Alternative Fuel ◽  
Air Gap ◽  
The Body ◽  
Injection Timing ◽  
Positive Trend ◽  
Piston Crown ◽  
Karanja Oil

The drawbacks associated with bio-fuels can be minimized by making modifications to combustion chamber. Modification of combustion chamber is achieved by providing an air gap in between the crown and the body of the piston with the top crown made of low thermal conductivity material. Experimentation is carried on a diesel engine with brass as piston crown material and karanja as test fuel, which is found to be a better alternative fuel based on the tests carried out prior to modification. Investigations are carried out on the performance of the engine with modified combustion chamber consisting of air gap insulated piston with 2 mm air gap with brass crown when fuelled with karanja oil. Comparative studies are made between the two configurations of engine with and without modification at an injection timing of 29obTDC. Performance, heat balance and emission plots are made with respect to brake power. Fuel consumption increased with modification. The mechanical and volumetric efficiencies are similar in both the cases. Indicated and brake thermal efficiencies got reduced with modification. But, it is good to see that HC and CO emissions are showing positive trend. Thus, the present investigation hints the possibility of improvements while making piston modification and providing air gap insulation.

OPTIMIZATION OF GAS-DIESEL ENGINE REGULATION AS A METHOD OF IMPROVING ITS ECOLOGICAL CHARACTERISTICS

2021 ◽  
pp. 28-32
Author(s):  
VALERIY L. CHUMAKOV ◽  
Keyword(s):  
Carbon Monoxide ◽  
Diesel Engine ◽  
Nitrogen Oxides ◽  
Diesel Fuel ◽  
Hydrocarbon Fuel ◽  
Load Range ◽  
Engine Operation ◽  
Exhaust Gases ◽  
Wide Range ◽  
Diesel Cycle

The paper shows some ways to improve the environmental characteristics of a diesel engine using gaseous hydrocarbon fuel and operating the engine in a gas-diesel cycle mode. Some possibilities to reduce toxic components of exhaust gases in a gas-diesel engine operating on liquefi ed propane-butane mixtures have been studied. Experiments carried out in a wide range of load from 10 to 100% and speed from 1400 to 2000 rpm showed that the gas-diesel engine provides a suffi ciently high level of diesel fuel replacement with gas hydrocarbon fuel. The authors indicate some eff ective ways to reduce the toxicity of exhaust gases. The engine power should be adjusted by the simultaneous supply of fuel, gas and throttling the air charge in the intake manifold. This method enriches the fi rst combusting portions to reduce nitrogen oxides and maintains the depletion of the main charge within the fl ammability limits of the gas-air charge to reduce carbon monoxide and hydrocarbons. The authors found that when the engine operates in a gas-diesel cycle mode, the power change provides a decrease in nitrogen oxide emissions of gas-diesel fuel only due to gas supply in almost the entire load range as compared to the pure diesel. At high loads (more than 80%) stable engine operation is ensured up to 90% of diesel fuel replaced by gas. Even at 10% of diesel fuel used the concentration of nitrogen oxides decreases by at least 15…20% as compared with a diesel engine in the entire load range. However, there is an increased emission of hydrocarbons and carbon monoxide in the exhaust gases. Further experimental studies have shown that optimization of the gas diesel regulation can reduce the mass emission of nitrogen oxides contained in exhaust gases in 2…3 times and greatly reduce the emission of incomplete combustion products – carbon monoxide and hydrocarbons.

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