Zbigniew J. Sroka

Some aspects of thermal load and operating indexes after downsizing for internal combustion engine

The twenty-first century started with many downsizing applications. This important trend in the engine technology has been constantly developed. There are questions about limits and on the other hand new solutions in the face of new materials, tribological discovery, lubrication oils, turbo- or supercharging, new control electronic system of the engine run, higher accuracy in designing, etc. Some of parameters of thermodynamics of working cycle and thermal load according to the downsizing engine parameters were considered in this article. The downsizing impacts on fuel economy and emission were analysed, too. The investigations were carried out with own measured data (i.e. pressure inside inlet manifold, temperature of engine wall) as well as data from references (for example material properties) and at the end the simulations were done. The essential achievements of the work are (a) downsizing factor (DSF) was defined first time in this article (nobody before), (b) because of possibility of exceeding thermal load in piston (as an example engine part) the changes of DSF has to be restricted to almost 0.95 giving changes of 0.85 for base cylinder diameter and 0.90 ratio of base volume for stroke, (c) the main goal of downsizing to reduce CO2 emission was results of all tests but it show only 10% benefit, and (d) it is possible to optimise the downsizing technology. So, the next research work will be focused on changes of super- and turbocharging as well as lean mixture combustion for better optimisation of downsizing.

AN IMPACT OF ENGINE DOWNSIZING ON CHANGE OF ENGINE WEIGHT

One of the trends for development of internal combustion engine is downsizing, which in its final form leads to reduction of fuel consumption and limitation of carbon dioxide concentration in the exhaust gases. The obvious effect of reducing the volume of a cylinder is to reduce the dimensions of the various components, e.g. piston with rings and pin, connecting rod, crankshaft, engine block etc. Changes of geometric dimensions also affect the change in mass of each element and consequently − the whole engine. Expected weight reduction will be a benefit in considering downsizing techniques as another significant development trend in automotive applications associated with a reduction in the weight of the complete vehicle – called “light weight vehicle”. The paper discusses the various forms of downsizing (by stroke, by diameter and mix) and their impacts on the changes in engine mass. The engine Subaru Flat 4, constructed with standard components in terms of design and materials was tested by virtual recognition in mass changes. Original drawings of components and sets have been simplified by for example does not account for chamfers and chops. When calculating also omitted the weight of typical accessories (e.g. fuel lines or electronic components), assuming that each considered option has the same equipment. The highest change in the weight of minus 7.27 % relative to the standard engine was done with downsizing by diameter and smallest one (-6.09 %) by downsizing mix.

The Project of Automation of Synthesis of Fatty Acid Methyl Ester as an Additive for Diesel Fuel

As petroleum fuels are getting higher in price day after day. I is important to search for an alternative fuel as crude oil will not last forever specially in this high economical and industrial progress. In a parallel way engineers and scientists are searching for additives for the current known fuel until they find the best alternative fuel which has to fulfill the pollution and technical requirements. One of the solution is to implement the idea of downsizing engine fuelled with alternative biodiesel - in this case manufactured by the transestrification by using microwave heating. The process needs automation to keep control for manufacturing efficiency and quality of fuel properties. Authors show the automation layout and present equipment of test stand. There is short summary of combustion engine emission tests, too.