Abdulkadir Yasar

Effect of inlet port on the flow in the cylinder of an internal combustion engine

Abstract In this study, the characteristics of flow emerging from the inlet of the intake port in the cylinder were investigated experimentally. A particle image velocimetry (PIV) technique was used to measure the velocity distribution in order to observe and analyse the flow behaviour. High-image-density PIV provided acquisition of patterns of instantaneous and averaged vorticity and velocity, revealing the detail of the flow characteristics in the cylinder cavity. With this measuring technique, it is possible to study the effect of intake valve geometry on the flow behaviours. The results showed that the flow structure changed substantially along the cylinder stroke due to the geometry of the intake valve port.

Estimation of relative humidity based on artificial neural network approach in the Aegean Region of Turkey

The aim of this study is to estimate the monthly mean relative humidity (MRH) values in the Aegean Region of Turkey with the help of the topographical and meteorological parameters based on artificial neural network (ANN) approach. The monthly MRH values were calculated from the measurement in the meteorological observing stations established in Izmir, Mugla, Aydin, Denizli, Usak, Manisa, Kutahya and Afyonkarahisar provinces between 2000 and 2006. Latitude, longitude, altitude, precipitation and months of the year were used in the input layer of the ANN network, while the MRH was used in output layer of the network. The ANN model was developed using MATLAB software, and then actual values were compared with those obtained by ANN and multi-linear regression methods. It seemed that the obtained values were in the acceptable error limits. It is concluded that the determination of relative humidity values is possible at any target point of the region where the measurement cannot be performed.

Estimation of human heat loss in five Mediterranean regions

This study investigates the effects of seasonal weather differences on the human bodys heat losses in the Mediterranean region of Turkey. The provinces of Adana, Antakya, Osmaniye, Mersin and Antalya were chosen for the research, and monthly atmospheric temperatures, relative humidity, wind speed and atmospheric pressure data from 2007 were used. In all these provinces, radiative, convective and evaporative heat losses from the human body based on skin surface and respiration were analyzed from meteorological data by using the heat balance equation. According to the results, the rate of radiative, convective and evaporative heat losses from the human body varies considerably from season to season. In all the provinces, 90% of heat loss was caused by heat transfer from the skin, with the remaining 10% taking place through respiration. Furthermore, radiative and convective heat loss through the skin reached the highest values in the winter months at approximately between 110 and 140W/m(2), with the lowest values coming in the summer months at roughly 30-50W/m(2).

The Influence of Diesel Fuel-biodiesel-ethanol-butanol Blends on the Performance and Emission Characteristics of a Diesel Engine

In this study, performance and exhaust emissions of a diesel engine fueled with Fuel A (60% diesel–30% biodiesel–5% ethanol–5% butanol) and Fuel B (40% diesel–50% biodiesel–5% ethanol–5% butanol) were investigated. The biodiesel produced from trap grease was obtained with an oil separator. Fuel A and Fuel B were tested in a single cylinder, four-stroke diesel engine at full load conditions. Compared with diesel fuel, the performance characteristics of blend fuels slightly deteriorated while the emission characteristics improved significantly. CO and HC emissions decreased by 87.01 and 87.50%, respectively.

Investigation of wind power density at different heights in the Gelibolu peninsula of Turkey

ABSTRACT This study aims to determine the wind characteristics and wind power potential of the Gelibolu peninsula in the Çanakkale region of Turkey. For this purpose, hourly average wind data observed at the Gelibolu meteorological station were used. The Weibull probability density functions and Weibull parameters of time-series of wind speed, mean wind speed, and mean wind power potential were determined for different heights as 10, 20, 30, 40, and 50 m. According to the results obtained at 10- and 50-m heights above the ground level, the annual wind speed varied from 6.85 to 8.58 m/s in this region, respectively. The annual wind power potential of the site was determined as 407 and 800 W/m2 for 10- and 50-m heights, respectively. These results indicate that the investigated site has a reasonable wind power potential for generating electricity.

Exhaust emissions of diesel engine with CuNO3 nano additive and butanol-diesel blends

This experimental study was focused on use of CuNO 3 as a fuel additive with butanol-diesel blends in diesel engine and its effects on fuel specifications and emission characteristics. With this purpose, CuNO 3 nano additive was mixed with diesel-butanol and each test fuel was analyzed to determine fuel specifications (density, viscosity, Cetane number, heating values and copper strip corrosion). A four stroke, four cylinder direct injection diesel engine was conducted to perform the test fuels. In conclusions, CuNO 3 nano additive with diesel-butanol blends improved the fuel specifications and exhaust emission characteristics of diesel engine.

Performance evaluation of a horizontal axis wind turbine in operation

ABSTRACT The operation of modern horizontal axis wind turbine (HAWT) includes a number of important factors, such as wind power (P), power coefficient (CP), axial flow induction factor (a), rotational speed (Ω), tip speed ratio (λ), and thrust force (T). The aerodynamic qualities of these aspects are evaluated and discussed in this study. For this aim, the measured data are obtained from the Sebenoba Wind Energy Power Plant (WEPP) that is located in the Sebenoba region in Hatay, Turkey, and a wind turbine with a capacity of 2 MW is selected for evaluation. According to the results obtained, the maximum turbine power output, maximum power coefficient, maximum axial flow induction factor, maximum thrust force, optimum rotational speed, probability density of optimum rotational speed, and optimum tip speed ratio are found to be 2 MW, 30%, 0.091, 140 kN, 16.11 rpm, 46.76%, and 7, respectively. This study has revealed that wind turbines must work under optimum conditions in order to extract as much energy as possible for approaching the ideal limit.

Effect of atmospheric temperature on exergy efficiency and destruction of a typical residential split air conditioning system

This work presents an experimental investigation on energy and exergy performance characteristics of a typical residential split air conditioning system. Analyses are performed for different atmospheric temperatures. On the basis of experimental data coefficient of performances (COP), exergy efficiencies (ψ) and exergy destructions (Ėxdest) of whole system and its each subunits are evaluated. The results also demonstrate that the atmospheric temperature (Tatm) rise affects the system performance as well as its performance of components substantially. The values of Ėxdest in the compressor and capillary tube increase with an increase of Tatm but the values of Ėxdest in the condenser and evaporator decrease with an increase of Tatm. When Tatm is risen from 20°C to 46°C; it is determined that power consumption (Ẇcomp) and Ėxdest of the air conditioning system are enhanced by 47.1% and 24.5%, respectively, but ψ is reduced by 38.8%.

The effects of seasonal weather differences on the bio-heat loss transferred from the human body in Antalya city

In this study, the effects of seasonal weather differences in Antalya city on the bio-heat losses from the human body have been investigated. For application, the monthly atmospheric temperature, relative humidity, wind speed and atmospheric pressure data, which are observed in 2006, have been used. The sensible and latent heat losses from the human body in terms of skin surface and respiration have been calculated and compared to each other. According to the obtained results, the latent and sensible heat losses from the human body have been varied considerably from season to season. Approximately ninety percent of bio-heat transferred from the human body to the surrounding is caused by the skin and the rest of 10% by respiration.