Experimental and numerical investigation on pressure characteristics of the dual-valve controlled fuel system for low-speed diesel engines

Maritime transport has made great contributions to the prosperity and development of the world economy. And the low-speed marine diesel engine has played an important role. However, with the aggravation of energy shortage and marine pollution, the development of diesel engines is facing unprecedented pressure. It is therefore urgent to improve the performance of fuel system of diesel engine. In this study, a simulation model of fuel system for a low-speed diesel engine was established. And the accuracy of the model was validated because of the good agreement between the experimental data and simulation results of system pressure characteristics. Based on the verified model, the influence of key parameters on system pressure characteristics was examined. The results show that the mass of pressure amplification piston and flow capacity of pressure amplification control valve have slightly influence on the pressure characteristics of the system. And the impact of diameter of big and small end of pressure amplification piston is more obvious than the first two, for they change the pressure amplification ratio. The diameter of high-pressure fuel tube is the most influential factor to system pressure characteristics. The reason is that the pressure accumulative effect is strengthened as it increases, which leads to a dramatical change happened to the movement of pressure amplification piston and the propagation of pressure waves.

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Free fall drop tests to determine low speed stability and base pressure characteristics for blunt planetary entry bodies

10.2514/6.1970-577 ◽

1970 ◽

Author(s):

P. BUCE

Keyword(s):

Free Fall ◽

Base Pressure ◽

Low Speed ◽

Drop Tests ◽

Speed Stability ◽

Planetary Entry ◽

Pressure Characteristics

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Numerical Investigation of the Solidity Effect on Linear Compressor Cascades

Volume 2A: Turbomachinery ◽

10.1115/gt2014-25532 ◽

2014 ◽

Cited By ~ 1

Author(s):

J. Sans ◽

M. Resmini ◽

J.-F. Brouckaert ◽

S. Hiernaux

Keyword(s):

Numerical Investigation ◽

State Of The Art ◽

Leading Edge ◽

Operating Conditions ◽

Compressor Cascade ◽

Minimum Loss ◽

Low Speed ◽

High Mach ◽

The Stability ◽

The Impact

Solidity in compressors is defined as the ratio of the aerodynamic chord over the peripheral distance between two adjacent blades, the pitch. This parameter is simply the inverse of the pitch-to-chord ratio generally used in turbines. Solidity must be selected at the earliest design phase, i.e. at the level of the meridional design and represents a crucial step in the whole design process. Most of the existing studies on this topic rely on low-speed compressor cascade correlations from Carter or Lieblein. The aim of this work is to update those correlations for state-of-the-art controlled diffusion blades, and extend their application to high Mach number flow regimes more typical of modern compressors. Another objective is also to improve the physical understanding of the solidity effect on compressor performance and stability. A numerical investigation has been performed using the commercial software FINE/Turbo. Two different blade profiles were selected and investigated in the compressible flow regime as an extension to the low-speed data on which the correlations are based. The first cascade uses a standard double circular arc profile, extensively referenced in the literature, while the second configuration uses a state-of-the-art CDB, representative of low pressure compressor stator mid-span profile. Both profiles have been designed with the same inlet and outlet metal angles and the same maximum thickness but the camber and thickness distributions, the stagger angle and the leading edge geometry of the CDB have been optimized. The determination of minimum loss, optimum incidence and deviation is addressed and compared with existing correlations for both configurations and various Mach numbers that have been selected in order to match typical booster stall and choke operating conditions. The emphasis is set on the minimum loss performance at mid-span. The impact of the solidity on the operating range and the stability of the cascade are also studied.

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Electronic control unit development and emissions evaluation for hydrogen–diesel dual-fuel engines

Advances in Mechanical Engineering ◽

10.1177/1687814018814076 ◽

2018 ◽

Vol 10 (12) ◽

pp. 168781401881407

Author(s):

Yasin Karagöz ◽

Majid Mohammad Sadeghi

Keyword(s):

Diesel Engines ◽

Working Condition ◽

Electronic Control Unit ◽

Control Unit ◽

Dual Fuel ◽

Hydrogen Energy ◽

Compression Ignition ◽

Electronic Control ◽

Fuel System ◽

Compression Ignition Engines

In this study, it was aimed to operate today’s compression ignition engines easily in dual-fuel mode with a developed electronic control unit. Especially, diesel engines with mechanical fuel system can be easily converted to common-rail fuel system with a developed electronic control unit. Also, with this developed electronic control unit, old technology compression ignition engines can be turned into dual-fuel mode easily. Thus, thanks to the flexibility of engine maps to be loaded into the electronic control unit, diesel engines can conveniently be operated with alternative gas fuels and diesel dual fuel. In particular, hydrogen, an alternative, environmentally friendly, and clean gas fuel, can easily be used with diesel engines by pilot spraying. Software and hardware development of electronic control unit are made, in order to operate a diesel engine with diesel+hydrogen dual fuel. Finally, developed electronic control unit was reviewed on 1500 r/min stable engine speed on different hydrogen energy rates (0%, 15%, 30%, and 45% hydrogen) according to thermic efficiency and emissions (CO, total unburned hydrocarbons, NOx, and smoke), and apart from NOx emissions, a significant improvement has been obtained. There was no increased NOx emission on 15% hydrogen working condition; however, on 45% hydrogen working condition, a dramatic increase arose.

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