International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

Considered are a number of difficulties arising when diesel engines operate on non-traditional fuels, which depend on fuel supply, mixture formation process in the cylinder, ignition principle in the combustion chamber, and peculiarities of combustion process flow according to required characteristics. Also to be considered is the qualitative load regulation implemented in diesel engines, where the air excess coefficient changes in a wide range depending on load α = 5 and more during idle and low power engine modes, while α =1.15–1.25 (gas-diesel cycle) when operating at nominal engine power mode. The permissible range of α variation significantly depends on the properties of the fuel used, combustion chamber shape, mixture formation process, self-ignition delay period, etc. Therefore, converting diesel engines to gaseous fuel ensures reduction of toxicity and smokiness in exhaust gases. From this perspective, the values of air excess coefficient according to diesel engine operation mode and the possibility of using different types of gaseous fuel for improving fuel properties are considered. As a result, improvement of both environmental and efficiency indicators is achieved, which is proven by both theoretical and experimental research results.

Three different types of combustion chambers for a gas turbine generator are discussed. The advantage of a hybrid gas turbine generator with one main and four co-cell combustion chambers is presented. The data from the experiment to be conducted on it are analyzed, and the issues of selecting an electric generator for a gas turbine generator using a simplified method are shown.

The development of market economic relations in Georgia requires the application of management principles that take into account the interests of management objects. Consequently, there is an objective need to apply logistics management methods at both micro and macro levels. In this study, a transport-logistics polygon has been investigated. The initial study of the transport-logistics polygon demonstrated that, at the initial stage of analysis, it is necessary to determine the possible combinations of logistics channels constituting the transport-logistics polygon. Since market relations provide a wide variety of transport service forms, the selection of potential local transport systems represents a search process. An algorithmic block diagram for studying the transport services market has been developed, along with recommendations for planning and organizing technological processes of local transport systems in Georgia.

the paper discusses the preparation of a fuel mixture consisting of liquefied gas and diesel fuel in marine diesel engines through the implementation of the gas–diesel process, where diesel fuel is used as pilot fuel. This approach reduces the ignition delay period compared to conventional liquid fuels, shortens combustion duration, and extends the flammability limits of the working mixture. Improved mixture formation leads to an increase in combustion rate and more complete combustion during the active combustion phase, causing the engine cycle to approach the Otto cycle. As a result, the environmental and performance characteristics of the diesel engine are significantly improved compared to conventional diesel and standard gas–diesel engines. The paper also analyzes the dependence of ignition delay on combustion parameters and fuel injection timing.

Hydrogen has a good environmental performance, high energy characteristics, high burning rate and low ignition temperature. In case of using hydrogen as a primary fuel in an internal combustion engine, there is a drop in power and detonation combustion at high load modes, so hydrogen is best used in a composition with the primary fuel.
In the mode of partial load, the hydrogen content in the fuel mixture decreases, and it should decrease as the load increases, and in the mode of full load, its amount is minimal, which will allow us to maintain the power characteristics, otherwise the power will decline. The main thing is to know in which mode what should be the ratio of hydrogen and the primary fuel, which ensures the normal flow of the operation process, which will result in primary fuel economy and reducing the toxicity of exhaust gases.
Based on the studies conducted, we can conclude that it is preferable for the engine to work with a high content of hydrogen in the fuel
mixture at no load and at light loads, its concentration should decrease as the load increases.

Analysis of claims incoming over the past years and the industry data on losses in supply chains allows to identify the most common risks and pay attention to the necessary measures to protect cargo during transportation.
Sometimes it is difficult to establish the relationships between a specific event and business, then logisticians use a probabilistic approach.
They predict how events can develop in the future. Each outcome is calculated and assessed as a separate risk.

Normally, maritime, air and surface transport assets powered by internal combustion engines are the major sources of chemical, biological and physical pollution of the environment. In the meantime, oil shortage and world oil prices are rising every year, which raises questions on the use of alternative energy sources that are not fossil fuels.
At the present time, natural gas as one of the types of fuel is widely and successfully used in surface transport owing to the availability of their sufficient reserves and good thermophysical characteristics. The article deals with the prospects for natural gas production in the sea and the possibilities of utilizing its energy source in small-capacity marine and river transport equipment in both diesel-cycle and directly converted to natural gas-powered diesel engines.

The article presents the analysis of the probable variability of cargo traffic flows within the transport corridors and the methods of improving the transport network taking into account the technical and economic criteria of transportation

Once a part of the Soviet Union, a backwater country, Georgia in a couple of years flips the script and rushes into tourism industry as one of the most popular emerging destinations on the Black Sea coast. With unprecedented number of tourists spotlighted by the leading international journals Georgia wins hearts of millions and becomes a revelation for the USA and Western EU countries.
This paper assesses current situation in Batumi Port that serves small cruise ships and explores potentials of cruise tourism development based on statistics, industry experts and investors reviews. The article uses a mixed method, a combination of qualitative and quantitative data analysis.
The findings show how Black Sea region will benefit from country’s cruise tourism development. Results of the study can be applied as basis for investment analysis of Georgian cruise industry