EXPERIMENTAL OPTIMIZATION OF AERODYNAMIC DRAG COEFFICIENT OF A MINIBUS MODEL WITH NON-SMOOTH SURFACE PLATE APPLICATION

In this study non-smooth surface plate application was experimentally investigated to flow control around a scaled minibus model in a wind tunnel. 1/15 scaled minibus model and non-smooth surface plate were designed in SolidWorks® Cad program and produced in 3-D printer. It was focused on decrease of drag coefficient of vehicle with non-smooth surface plate by reducing flow separation. The experimental tests carried out 4 free stream velocities between the speed of 13.90-27.40 m/s and 2.62x105-5.18x105 Reynolds numbers. In wind tunnel tests Reynolds number independence was used to ensure dynamic similarity. The blockage rate was 10.68 %. It was determined that the using of non-smooth surface plate e on the front roof area of minibus model decreased to drag coefficient by an average of 1.03%. This reduction rate can decrease fuel consumption of vehicle about 0.5% at high speeds

The improving of affecting aerodynamic drag force to a vehicle with rear deck spoiler

Bu çalışmada, 1/15 ölçekli bir minibüs modeline etki eden sürükleme kuvveti spoiler uygulaması ile iyileştirilmiştir. Model minibüse ait çizim datası Solid Works® Programında oluşturulmuş ve bir bagaj üstü spoileri geliştirilmiştir. Spoiler minibüs bagajı üstüne 10 mm (L/H=0.065) ve 15 mm (L/H=0.1) mesafelerinde konumlandırılmıştır. Bu spoiler kullanımı ile minibüsün arka bölümünde oluşan negatif basınç alanının azaltılması amaçlanmıştır. Geliştirilen spoiler ile kara taşıtlarının toplam aerodinamik direnç katsayılarının büyük bir kısmını oluşturan negatif basınç kaynaklı sürükleme kuvveti azaltılmıştır. Minibüs modeline etki eden sürükleme kuvvetleri Fluent© programında 5 değişik serbest akış hızı ve Reynolds sayısında belirlenmiştir. Aerodinamik direnç katsayısı sırası ile ortalama (CD) % 4.96 ve %5.27 azaltılmıştır. Model minibüs etrafındaki akış yapısı ve taşıt gövdesi üzerindeki basınç dağılımına ait akış görüntülemeleri yapılmıştır.In this study, the drag force which affecting on a 1/15 scaled minibus model was improved by rear deck spoiler. The drawing data of the model minibus was created in the Solid Works® Program and a rear deck spoiler was designed. The spoiler was mounted on rear deck in 10 mm (L/H=0.065) and 15 mm (L/H=0.1) distances. It was aimed to decrease of negative pressure area where the back of the minibus by using of this spoiler. The negative pressure-based drag force which forms a large part of the total aerodynamic drag coefficients of land vehicles was decreased with this method. The drag forces which effect on the minibus model was determined in 5 different free flow velocities and Reynolds numbers in Fluent© program. Aerodynamic drag coefficient (CD) was decreased average 4.96% and 5.27% respectively. The flow visualizations of flow structure around model minibus and pressure distribution on vehicle body were carried out

EXPERIMENTAL OPTIMIZATION OF AERODYNAMIC DRAG COEFFICIENT OF A MINIBUS MODEL WITH NON-SMOOTH SURFACE PLATE APPLICATION

In this study non-smooth surface plate application was experimentally investigated to flow control around a scaled minibus model in a wind tunnel. 1/15 scaled minibus model and non-smooth surface plate were designed in SolidWorks® Cad program and produced in 3-D printer. It was focused on decrease of drag coefficient of vehicle with non-smooth surface plate by reducing flow separation. The experimental tests carried out 4 free stream velocities between the speed of 13.90-27.40 m/s and 2.62x105-5.18x105 Reynolds numbers. In wind tunnel tests Reynolds number independence was used to ensure dynamic similarity. The blockage rate was 10.68 %. It was determined that the using of non-smooth surface plate e on the front roof area of minibus model decreased to drag coefficient by an average of 1.03%. This reduction rate can decrease fuel consumption of vehicle about 0.5% at high speeds

OPTIMIZATION OF THERMOPHYSICAL PROPERTIES, COMBUSTION PERFORMANCE AND HARMFUL EXHAUST GASES OF BIODIESEL FUEL WITH NANOPARTICLE ADDITIVES

Increasing use of diesel products causes decrease of oil reserves, global warming, increase in the world average and adverse effects on human health and the environment. Emissions from combustion in engines are directly related to the quality, properties and combustion characteristics of the fuel. Since the physical and chemical properties of the fuel affect the atomization characteristics, it is important for increasing the combustion efficiency. The most important fuel properties affecting the combustion of diesel fuel are cetane number, viscosity, density and calorific value. There are many applications in improving the chemical and physical properties of fuel. One of them is nanoparticle (NPs) additives adding in fuel. In this study, it was aimed to improve fuel properties with optimum additive ratio by adding CeO2, TiO2 and Co3O4 nanoparticle additives into biodiesel which are produced from cotton and canola oil. The effects of NPs additives in fuel properties such as viscosity, density, lower calorific value and flash points were investigated

OPTIMIZATION OF THERMOPHYSICAL PROPERTIES, COMBUSTION PERFORMANCE AND HARMFUL EXHAUST GASES OF BIODIESEL FUEL WITH NANOPARTICLE ADDITIVES

Increasing use of diesel products causes decrease of oil reserves, global warming, increase in the world average and adverse effects on human health and the environment. Emissions from combustion in engines are directly related to the quality, properties and combustion characteristics of the fuel. Since the physical and chemical properties of the fuel affect the atomization characteristics, it is important for increasing the combustion efficiency. The most important fuel properties affecting the combustion of diesel fuel are cetane number, viscosity, density and calorific value. There are many applications in improving the chemical and physical properties of fuel. One of them is nanoparticle (NPs) additives adding in fuel. In this study, it was aimed to improve fuel properties with optimum additive ratio by adding CeO2, TiO2 and Co3O4 nanoparticle additives into biodiesel which are produced from cotton and canola oil. The effects of NPs additives in fuel properties such as viscosity, density, lower calorific value and flash points were investigated

The Investigation Of Aerodynamic Drags For Truck And Truck Trailer Combinations

Bu çalışmada, rüzgâr tüneli içine yerleştirilmiş 1/32 ölçekli çekici ve römorktan oluşan bir ağır vasıta aracın modeli üzerinde 6 farklı hızda yüzey basıncı ve kuvvet ölçümü gerçekleştirilmiştir. Çekicinin rüzgar tüneli testleri 59 000 - 317 000 Reynolds sayılarında yapılmıştır. Çekici römork kombinasyonunun rüzgâr tüneli testleri ise 156 000 - 844 000 Reynolds sayılarında yapılmıştır. Çekici ve römork üzerindeki basınç katsayısı (CP) dağılımı ve aerodinamik direnç katsayıları (CD) deneysel olarak tespit edilmiştir. Yapılan deneysel çalışmalarda kinematik benzerlik sağlanmış ve blokaj etkileri ihmal edilmiştir. Deneysel çalışmalarda dinamik benzerlik şartında Reynolds sayısı bağımsızlığı kullanılmıştır. Çekiciye römork ilavesinin aerodinamik direnç katsayısına etkisi belirlenmiştir. Yüzey basıncı ve kuvvet ölçümleri aynı deney şartlarında Fluent® programında sayısal olarak yapılmış ve çekici römork etrafındaki akış görüntülemeleri elde edilmiştir. Çekici ve çekici römork kombinasyonun aerodinamik direnç katsayıları (CD) sayısal olarak hesaplanmıştır. Deneysel çalışma sonuçları sayısal çalışma sonuçları ile karşılaştırılarak sayısal çalışma sonuçları doğrulanmıştır. Basınç katsayısı dağılımları ve akış görüntülemeleri sonucunda çekici römork üzerinde aerodinamik direnç oluşturan bölgeler tespit edilmiş ve pasif akış kontrolü yöntemleri ile aerodinamik iyileşme elde edilmiştir. Model 1 aracında spoiler yapısı iyileştirilerek % 11,37, model 2 aracında spoiler ile birlikte römork arka uzantısı eklenerek % 12,88, model 3 aracında spoiler ve römork arka uzantısı ile birlikte yan rüzgâr kırıcı eklenerek % 20,11 oranında aerodinamik iyileşme elde edilmiştir. Model 4 aracında ise model 2 aracının çekici römork arası körükle kapatılarak toplam % 23,85 oranında aerodinamik iyileşme elde edilmiştir.In this study, at 6 different speed surface pressure and force measurement were measured on a heavy vehicle model consisted of truck and in 1/32 scale trailer placed wind tunnel. The wind tunnel tests were made for trailer on 59 000 - 317 000 Reynolds numbers. The wind tunnel tests of truck trailer combination were made on 156 000 - 844 000 Reynolds numbers. The pressure coefficient (CP) distribution and aerodynamic drag coefficient (CD) on truck and trailer were experimentally determined. In experimental studies, kinematic similarity was provided and blocking effects were neglected. In the dynamic similarity condition, the independence of Reynolds number was used in the experimental studies. The effect of the addition of trailer to the truck on aerodynamic drag coefficient was determined. The surface pressure and force measurements were performed as numerically in the same experimental conditions at Fluent® software, and the flow visualization around of the truck and the trailer was obtained. The aerodynamic drag coefficients of the combination of the truck and the truck trailer were numerically calculated. Numerical study results were verified as experimental study results were being compared with experimental study results. The pressure coefficient distributions and the regions forming aerodynamic resistance on the truck trailer at the end of the flow visualization were determined and aerodynamic improvement was obtained with passive flow control methods. As the structure of spoilers was being improved on model 1 truck trailer, % 11,37 aerodynamic improvements, adding trailer rear extension with spoiler on model 2 truck trailer, % 12,88 aerodynamic improvements and trailer spoiler with trailer rear extension by adding side wind breaker on model 3 truck trailer, % 20,11 aerodynamic improvements were obtained. As between truck and trailer of model 2 was being closed with articulated, totally % 23,85 improvements were obtained on model 4 truck trailer

The effects of the use of different catalyst in the cotton seed methyl esters production on the engine emissions performance

WOS: 000297087600064In this study the effect of mixture of cottonseed oil methyl ester-diesel, which is one of renewable energy resource, on exhaust emission and the effect of utilizing different catalyst in production of biodiesel on exhaust emission are investigated experimentally. Utilizing KOH as catalyst has increased HC emissions 54,58% and CO emissions 18,10% in spite of decreasing CO2 emissions 15,45%, NOx emissions 28,45% on average comparing to NaOH. 93% of CO2 emissions of pollutants in the atmosphere, 57% of HC, 39% of NOx and 1% of SO2 is vehicle sourced. Most important polluter are particulate matter emissions (PM) and NOx for diesel engines. It has been observed that use of cotton seed methyl ester as engine fuel is decreased to NO emission in our study

THE IMPROVEMENT OF DRAG FORCE ON A TRUCK TRAILER VEHICLE BY PASSIVE FLOW CONTROL METHODS

WOS: 000377235800014In this study, the drag force measurements were carried out for a 1/32 scaled heavy vehicle model, consisted of truck and trailer, placed in the wind tunnel. The wind tunnel tests were also performed for 9 different free stream velocities in the range of Reynolds number between 113 000 and 453 000. The drag coefficients (CD) of the truck and trailer combination were experimentally determined. In the experimental studies, kinematic similarity was provided except moving road and blockage effect is ignored due to the small blockage ratio of 3%. The independence of Reynolds number was used for the dynamic similarity condition. The regions forming aerodynamic resistance on the truck trailer were determined and aerodynamic improvement was obtained with passive flow control methods. In the case of model 1 of truck and trailer, the aerodynamic improvement is obtained as % 15,71 by improving geometry of spoilers. % 22,46 aerodynamic improvements is also obtained by using passive air channel with a spoiler for the case of model 2. For the case of model 3, by adding a redirector to the model 2, the improvement is reached to % 25,58