Person:
GÜL, MEHMET ZAFER

Profile Picture

Email Address

Birth Date

Research Projects

Organizational Units

OrgUnit Logo
Organizational Unit

Job Title

Last Name

GÜL

First Name

MEHMET ZAFER

Name

Filters

2020 - 20212
Reset filters

Settings

Subject: SYSTEM ×

Search Results

Now showing 1 - 2 of 2
  • No Thumbnail Available
    PublicationMetadata only
    Effects of injection strategy and combustion chamber modification on a single-cylinder diesel engine
    (ELSEVIER SCI LTD, 2020) GÜL, MEHMET ZAFER; Sener, Ramazan; Yangaz, Murat Umut; Gul, Mehmet Zafer
    The diesel engine is widely used due to its thermal efficiency, reliability and fuel economy, while diesel engine emissions are harmful to the environment and human health. Therefore, the standards (EPA, Tier, NRE-v/c standards, etc.) limit the exhaust emission of engines around the world. The most successful method of reducing emissions is to optimize the combustion chamber and the fluid motion inside the engine. In this study, experimental and numerical methods were used in a diesel engine to analyze fluid motion, spray, combustion process, and exhaust emissions. A new type of swirl piston bowls and a reentrant piston bowl were utilized on a baseline diesel engine. Different spray angles and injection pressures were applied and results were compared with the baseline design. Results show that the piston bowl shape has a critical influence on engine performance and emissions. Since the multi-swirl piston bowl (MSB) and double-swirl piston bowl (DSB) design increases in-cylinder swirl and turbulence, it contributes to reducing emissions and improving the combustion process. Increasing spray angle and injection pressure and using of DSB can reduce the soot emissions by 81%. DSB and MSB improve the combustion process but also increase NOx emissions due to increased in-cylinder temperature. On the other hand, NOx emissions may also be reduced if the injection parameters of the engine are optimized to provide the same power with the new swirl bowls.
  • No Thumbnail Available
    PublicationMetadata only
    Optimization of the combustion chamber geometry and injection parameters on a light-duty diesel engine for emission minimization using multi-objective genetic algorithm
    (ELSEVIER SCI LTD, 2021) GÜL, MEHMET ZAFER; Sener, Ramazan; Gul, M. Zafer
    Combustion efficiency and exhaust emission of the compression-ignition engines are highly dependent on the combustion chamber design. In this study, shape optimization was performed to reduce the emissions and maximize the combustion efficiency of a compression ignition engine with the guidance of computational fluid dynamics (CFD). The aim was to optimize diesel combustion efficiency while maintaining engine power and torque. A double-swirl piston bowl is used, and the bowl depth, bowl diameter, and other dimensions of the piston bowl are optimized to minimize the soot and NOX emission while meeting the IMEP target. The spray angle of the injector, SOI, and injector protrusion were parametrized to meet the optimization targets. The numerical model was developed using Converge software. CAESES software and multi-objective genetic algorithm (MOGA) were used to automatically change the chamber design parameters and to optimize the piston bowl geometry. A total of 104 different combustion chamber designs and 23 varied injection parameters were determined parametrically and the optimum case was decided with the MOGA. A comprehensive optimization study was carried out using experimental, CFD, and MOGA methods. Compared to the baseline design, the optimized new piston bowl design has provided enhanced in-cylinder air utilization and rapid mixing-controlled combustion, resulting in enhanced fuel efficiency. The optimized design emits remarkably lower NOX and soot emissions.