Experimental Investigation of Using Ethanol-Gasoline 750 on the Performance and Exhaust Emmision of Spark İgnition Engine in Iraq

في هذه الدراسة، تأثير أضافه الايثانول ذات نقاوة 99.9% إلى الكازولين ((750في نسب خلط تتراوح من E0%-E50%)) أي زيادة E10% عنده كل نسبه خلط على أداء محرك يعمل بالشرارة وانبعاث غازات العادم. في هذه التجربة يتضمن محرك أحادي الاسطوانة، رباعي الأشواط. اختبارات الأداء كانت تحمل على القدرة المكبحيه, الاستهلاك النوعي للوقود المكبحي, والكفاءة الحرارية المكبحيه. من حيث الانبعاثات غازات العادم كانت على تركيز أول اوكسيد الكاربون CO، ثاني اوكسيد الكارب ونCO2، وكميه الهايدروكاربونات المنبعثة. هذا العمل أجريت تحت مختلف السرعة تتراوح من 1500-2500rpm أي زيادة السرعة 250rpm في حالتين حمل وبدون حمل. محصله النتائج وجود زيادة في القدرة المكبحية, الكفاءة الحرارية المكبحية, وأيضا نقصان في استهلاك الوقود النوعي المكبحي. إن أضافه الايثانول إلى الكازولين 750 أدى إلى نقصان في تراكيز CO, HC المبعثات من غازات العادم وأيضا زيادة في تركيز CO2. وجد ايضا عنده زيادة سرعة المحرك مع أزديادة في نسب الخلط أدئ إلى زيادة درجه حرارة غازات العادم.The influences of adding pure ethanol 99.9% (0E, 10E, 20E, 30E, 40E, 50E,) to gasoline 750 blends on the performance of the engine and characteristic emission of spark ignition (SI) engine are conducted in the present study. The Internal combustion engine that employed in the experiment has specifications of a (singl – cylinder) and 4- stroke (SI). Performance tests are carried out for brake power (Bp), brake specific fuel consumption (Bsfc), brake thermal efficiency (ηBth), for carbon dioxide (CO2), carbon-monoxide (CO) and hydrocarbon born (HC) emissions. The measurements are recorded under several engine speeds from (1500-2500rpm) for two cases, the first with load and the second case without load. The experimental result showed that ethanol- gasoline750 blends fuel increases the (Bp), and (ηBth) about 2.61% and 30.9%, respectively for all engine speeds. Also, the (Bsfc) a bit decreases about 4.97%. By increasing the ethanol- gasoline750 blend fuel decreases the CO, HC emissions about 4.67% and 6.4%, respectively, where the CO2 concentration increases about 6.1%. It was detected that the temperature of exhaust gas increases about 33.60%, as engine speed increase

CFD ANALYSIS OF THE EFFECT OF PARABOLIC TAPER DISTRIBUTION OF AN UNTWISTED HELICOPTER ROTOR BLADE

The effect of parabolic taper distribution along the span of a helicopter rotor blade is analyzed in terms of the rotor thrust, torque and Figure of Merit. Various maximum chord length values are investigated. The Reynolds Averaged Navier-Stokes computations are done using the FINE/Turbo flow solver developed by NUMECA International. The Spalart-Allmaras turbulence model is used to calculate the eddy viscosity. The baseline blade is selected as the Caradonna-Tung rotor blade. Different blade shapes were generated by setting the maximum chord length at different spanwise locations for the same planform area as the baseline blade. Three optimum cases are observed: maximum Figure of Merit, maximum thrust for the baseline Figure of Merit and maximum Figure of Merit for the baseline thrust. Those optimum cases are noticed when the maximum chord length is 1.3 times the baseline blade chord length

Comparison of Optimum Spline-Based Probability Density Functions to Parametric Distributions for the Wind Speed Data in Terms of Annual Energy Production

The common approach to wind energy feasibility studies is to use Weibull distribution for wind speed data to estimate the annual energy production (AEP). However, if the wind speed data has more than one mode in the probability density, the conventional distributions including Weibull fail to fit the wind speed data. This highly affects the technical and economic assessment of a wind energy project by causing crucial errors. This paper presents a novel way to define the probability density for wind speed data using splines. The splines are determined as a solution of constrained optimization problems. The constraints are the characteristics of probability density functions. The proposed method is implemented for different wind speed distributions including multimodal data and compared with Weibull, Weibull and Weibull and Beta Exponentiated Power Lindley (BEPL) distributions. It is also compared with two other nonparametric distributions. The results show that the spline-based probability density functions produce a minimum fitting error for all the analyzed cases. The AEP calculated based on this method is considered to have high fidelity, which will decrease the investment risk

A NUMERICAL ASSESSMENT OF ATMOSPHERIC BOUNDARY LAYER SIMULATION INSIDE TWO DIFFERENT BOUNDARY LAYER WIND TUNNELS

A new large scale wind tunnel is under development at METU Center for Wind Energy (RÜZGEM). This wind tunnel is a closed-loop multi-purpose wind tunnel with a 3 m x 7 m x 20 m boundary layer test section. Inside this test section the atmospheric boundary layer (ABL) will be simulated using the spire-roughness element technique in order to represent different terrain exposures (or categories) as defined by American Society of Civil Engineers (ASCE). Since no experimental data are available yet, Computational Fluid Dynamics (CFD) will be implemented as a tool in order to provide an initial assessment for the simulation of the ABL. However, in order to validate the CFD approach, another wind tunnel test case from literature will be used for comparison. This wind tunnel has 1.82 m x 1.82 m x 9.8 m test section. Four different test cases have been simulated and the results show reasonable agreement between the experiments and numerical results in terms of velocity profiles, power law exponents and boundary layer parameters