STRATEGY FOR DIESEL ROTARY ENGINE WITH COMMON RAIL INJECTION SYSTEM

A direct injection low compression ratios diesel rotary engine is designed and studied to find the appropriate application of the electronic controlled high pressure common rail injection system. Current development focuses on the applied fuel injection and ignition strategies, especially concerning the combustion configurations of injectors, ignition source, and combustion chamber. The prototype engine, equipped with Bosch common rail system and high performance electronic control unit （ECU）, is designed correspondingly. Studies show that the integration of a common rail injection system and the main and pilot duel injectors configurations, assisted with glow plug ignition device and flexible ECU, represents a promising approach to improve the potential of the low compression ratios diesel rotary engine. Currently the engine can run at 6 kr · min^-1 steadily and the power is about 68 kW/（4 kr ·min^- 1）.

Optimization of Combustion Characteristics and Fuel Injection Timing of a New Type Dual-Pit Combustor Rotary Engine

In order to improve the performance of the rotary engine,this paper has designed a new type of dual-pit rotary engine combustion chamber structure,and compares the combustion and emission characteristics with the rotary engine with a traditional combustion chamber.The existence of the dual-pit combustion chamber strengthens the overall vortex intensity in the cylinder,effectively promotes the mixing process of fuel and air in the cylinder,the maximum combustion pressure in the cylinder increased by 8.6%,significantly increases the diffusion combustion speed,and significantly improves the dynamic performance of the rotary engine.On this basis,the effects of fuel injection timing parameters on fuel distribution,combustion and emission characteristics were studied.Fuel distribution is more even and dispersed during injection in the later stage of compression.When the fuel injection timing was 105°BTDC in the middle of the compression phase,the matching effect of fuel distribution law and ignition scheme was the best.When the injection timing was 75°BTDC and 85°BTDC in the late compression stage,the mass fraction of NOx remained at a low level.The correlation between soot generation and the change of fuel injection timing was weak.When the injection time was 85°BTDC,the soot generation remained at a relatively high level.

Study on Biomass Gasified Generator Using Rotary Engine

The purpose of this study is to investigate the biomass gasification system for power supply to introduce in rural communities of developing countries.The study was conducted using biomass gasification system(20 kW)which developed at Ashikaga University.In general,for small scale power supply system using biomass gasification,reciprocate type engine or modified diesel engine are attached for power generation.However,biomass gasifier produces tar and it causes problems on smooth movement of piston in the reciprocate engine.To avoid effect by tar,the system is comprised the rotary engine coupled to a generator since there is no piston inside the engine.As for gasification system,downdraft gasifier is designed and installed.In this study woody biomass was gasified.The gasifier performance was evaluated with respect to fuel consumption rate.The rotary engine-generator system was evaluated in terms of power generation efficiency.Result of this study shows that fuel consumption rate was about 30 kg/h,gasification efficiency was about 63.4%and efficiency of rotary engine system was about 9.4%.

Experimental Investigation on the Effect of Blending Ethanol on Combustion Characteristic and Idle Performance in a Gasoline Rotary Engine

Rotary engine is an ideal electric vehicle range extender.However,the combustion chamber of rotary engine is very narrow and long at the top dead center,which is detrimental to fuel combustion performance.In order to improve its economic and emission performance,this paper built an ethanol/gasoline dual-fuel rotary engine test bench,and the combustion and emission performance of gasoline rotary engine under five ethanol blending ratios were studied.The experimental results showed that,when the fuel pulse width is not adjusted,since the calorific value of ethanol is lower than that of gasoline and the latent heat of vaporization of ethanol is higher than that of gasoline,the addition of ethanol in gasoline lowers the peak pressure.When the ethanol blending ratio reaches 30 vol%,the pressure curve shows a distinct double peak.Under the theoretical air-fuel ratio condition,mixing ethanol in gasoline increases the heat release rate,shortens the combustion duration while prolonging delay period.After blending ethanol,HC,CO and NO_(x)emissions have been reduced under various operating conditions.Excessive ethanol blending ratio increases NO_(x)emissions and increases cycle variation coefficient.When the ethanol blending ratio is 15 vol%,it has better power ability while maintaining low cycle variation coefficient and emissions.

Prediction of rotary drilling penetration rate in iron ore oxides using rock engineering system

Prediction of the drilling penetration rate is one of the important parameters in mining operations. This parameter has a direct impact on the mine planning and cost of mining operations, Generally, effective parameters on the penetration rate is divided into two classes： rock mass properties and specifications of the machine, The chemical components of intact rock have a direct effect in determining rock mechan- ical properties, Theses parameters usually have not been investigated in any research on the rock drill- ability, In this study, physical and mechanical properties of iron ore were studied based on the amount of magnetite percent, According to the results of the tests, the effective parameters on the pen- etration rate of the rotary drilling machines were divided into three classes： specifications of the machi- nes, rock mass properties and chemical component of intact rock, Then, the rock drillahility was studied using rock engineering systems, The results showed that feed, rotation, rock mass index and iron oxide percent have important effect on penetration rate, Then a quadratic equation with 0,896 determination coefficient has been obtained, Also, the results showed that chemical components can he described as new parameters in rotary drill penetration rate,

Three-dimensional simulation of a novel rotary-piston engine in the motoring mode

In this simulation study,the flow and thermal characteristics of a novel rotarypiston engine,which is a kind of internal combustion engines,were investigated by computational fluid dynamics and the finite volume method.The structure of this engine is different to others,mainly for having 24 cylinders during the motoring mode.As a novel engine,creation of numerical models based on Reynolds average Navier Stokes(RANS)simulation and analysis of various speed engines on the flow and thermal fields during intake and compression strokes are the focus of this work.The results were illustrated in term of the streamline patterns,in-cylinder temperature and pressure profile,swirl ratio(SR),wall heat flux,and turbulent velocity fluctuation.The present study indicates that,the mean pressure,temperature trace,and heat loss from the wall increase when switching to a higher engine speed.The temperature distribution reveals that the maximum temperature is restricted in the center of the combustion chamber near top dead center(TDC).Also,the maximum amount of turbulent velocity and swirl ratio are achieved at the beginning of the intake stroke and near TDC.It is observed that the obtained numerical results are in general agreement with the available experimental data.