A deep understanding of the ignition characteristics of syngas-diesel under different lambda values is essential for the application of dual-fuel combustion. In this study, the effect of increasing the lambda value was examined along with the emission characteristics and engine performance of syngas-diesel dual-fuel engines under a constant syngas-to-diesel substitution ratio of 52% at 2000 rpm engine speed. The work involved computational fluid dynamics analysis related to combustion for a four-stroke single-cylinder direct-injection engine. Combustion analysis was carried out using ANSYS Workbench (FLUENT) V16.1 software. According to the simulation results, the maximum pressure, temperature, and nitric oxide emission inside the combustion chamber increased with each increase in the value of lambda, while the emission of carbon dioxide and carbon monoxide decreased inside the engine.

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Efficiency of a wing is sufficient at stall angle of attack and breakdown by effecting turbulent flow intensity on upper wing surface which is destroyed the airflow pattern and generated adverse pressure, backflow airstream and forward transition separation point movement closely to the leading edge of the wing. To enhancement a wing efficiency factor at high angle of attacks in this research is using partially sucking adverse pressure to delay the separation point to control the backflow rate and expelling it through the wing tips ends using tangential suction slot channel without using any mechanical means depending on differential static pressure between adverse pressure and the static pressure generated on both win tips ends. Numerical CFD analysis has been managed the case study of the effect suction slot channel located on the upper wing surface at (70%) of the wing chord from the leading edge as a proposed modified wing model of the Cessna 172 Skyhawk half wing at angle of attacks (10°, 12°, 14°, 16°, 18°, 20°, 22°, 24°). The analysis study was conducted at stall speed (90 km/hr.) without flaps where it is equal (25 m/sec). The results of the analytical shows at the range of angle of attacks were chosen between (10° to 24°), lift coefficient CL increased (3.757%), drag coefficient CD is decreased (0.530%) and the wing efficiency lift to drag ratio Δ(CL/CD) is increased to (5.712%) while Δ(CD/CL) is decreased to (5.231%) which these parameters reflected to enhancement the wing to reduce required power at the minimum speed, increase angle of climb and decrease angle of descent reduce landing distance with high angle of attacks.

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