removal and hiding a part of the speech indicate to the brevity. not mentioning to the part of the sentence, which in some cases can be considered one of the sentence elements, is one of the most important topics that frequently seen in the quran. one of the omissions in the quran is elliptical answer of condition (shart). identifying the elliptical answer of condition in quran and guessing it,...

Anumerical study was conducted to investigate the effects of airfoil thickness on the thrust generation of plunging airfoils and to assess the contributions of pressure and viscous forces in flapping propulsion. A series of NACA symmetric airfoils with thickness ratio ranging from 4.0% to 20.0% of the airfoil chord length were used in the present study to undertake a same sinusoid plunging moti...

Electricity is a strategic energy resource and very important for the livelihood of many people. The government has tried to free Indonesia from electricity crisis trying find alternative uses new renewable (EBT). committed that NRE will continue be developed ensure security in meet growing demand electricity. set target 23% share clean national mix 2025 31% 2030 through National Energy Policy ...

The influence of periodic excitation from synthetic jet actuators, SJA, on boundary layer separation and reattachment over a NACA 0025 airfoil at a low Reynolds number is studied. All experiments were performed in a low-turbulence recirculating wind tunnel at a Reynolds number of 100,000 and angle of attack of α = 5◦. Mounted below the surface of the airfoil, the SJA consists of four (32.77mm d...

Unlike in the case of high Reynolds number airfoil, selecting a turbulent closure model for low airfoil is still challenge. A used not necessarily suitable due to presence separation bubbles airfoil. In this study, we two simple models, Spalart-Allmaras and k- , calculating thrust coefficient as propeller determine their accuracy. It was found that there significant discrepancy between numerica...

The present article seek to investigate the function of elliptical steel damper function in steel frames seismic resisting. The elliptical damper is a kind of earthquake energy dissipater in structure which acts based on the steel yielding feature. Thus, this damper in frame lateral displacement mechanism is expected to have a satisfying hysteretic behavior in terms of energy absorption is on a...

the present article seek to investigate the function of elliptical steel damper function in steel frames seismic resisting. the elliptical damper is a kind of earthquake energy dissipater in structure which acts based on the steel yielding feature. thus, this damper in frame lateral displacement mechanism is expected to have a satisfying hysteretic behavior in terms of energy absorption is on a...

in this paper, a method based on binary-coded genetic algorithm is proposed to explore an optimization method, for obtaining an optimal elliptical tank. this optimization method enhances the rollover threshold of a tank vehicle, especially under partial filling conditions. minimizing the overturning moment imposed on the vehicle due to c.g. height of the liquid load, lateral acceleration and ca...

The flow mechanism leading to the enhanced performance of a discrete co-flow jet (dCFJ) airfoil is investigated. Flow visualization and DPIV are used to analyze the difference between the flow along discrete jets and over the tabs used for discretization of the slot jet. Results show that the entrainment is uniform over the leading jet as long as the tab size is small enough. The jets expand sp...

In this contribution, the unsteady, viscous and two dimensional flow over a plunging NACA0012 airfoil was simulated using a high-order numerical method associated with a moving frame of reference technique. The goal of using a high-order numerical method is to characterize heaving airfoil wakes with very fine temporal and spatial resolutions. This characterization is essential in understanding ...