ملخص البحث :

A propeller works like a rotating wing, generating lift in the direction of revolution. Many earlier propeller optimization algorithms have been devised;however, they often identify the best thrust coefficient at a constant power coefficient and vice versa.This studywill find the optimal value of the thrust coefficient and the power coefficient togetherto find the optimum value of the thrust and the lowest value of the power at the same time. All hypotheses were based on a Simple Blade Element Theory Blade. More than 80 different styles, brands, and types of propellers in 2-blade configuration with diameters ranging from 2.5 to 19 inches and varied pitch values were tested in this article. The UIUC Propeller Database was used to get the data for the baseline propeller.Propeller style, diameter, pitch angle, rotational speed, thrust coefficient, and power coefficientare the inputs for the optimization. The result shows that the algorithm can find the optimal propeller specifications by determining the factor of interest in the thrust coefficient and the power coefficient, when the interest in the thrust coefficient is 100%, the algorithm will neglect the effect of the power coefficient and vice versa.

ملخص البحث :

In this paper, the thermal behavior of concrete blocks with different rubber ratios was examined experimentally. The rubber of 0%, 5%, 10%, 15%, and 20% used instead of fine aggregate in a concrete block raw materials. The size of the rubber granules used in this study is between 0-1 mm. The concrete approved mixing ratios are 1:2:1. The indoor solar simulator with 700 w/m2 light intensity was applied on the external surface of each block and thermocouples were used to measure the temperature on the external and internal surfaces. The other block surfaces are insulated. The results indicated that the use of rubber aggregate with the concrete block reduced the inner surface temperature by increasing the thermal resistance of the heat flux. ​For 20% rubber added, produce 8.5% low-weighted construction materials and with high thermal resistance that works to save energy consumed in the building sector.

ملخص البحث :

The present study considered an impingement jet using hybrid nanofluid CuO–Cu/water. A single rounded nozzle was used to impinge a turbulent coolant (water) on the hot circular plate at Reynold’s number range of (5,000–15,000). CuO–Cu nanoparticles were physically synthesized at 50 nm size and dispersed by one-step preparation method. The experimentations were conducted with nanoparticle concentrations range of (0.2–1%) by volume. The results showed that the presence of hybrid nanoparticles exhibits a significant improvement in the overall thermal performance of the working fluid. Where the gained heat interpreted by the Nusselt number was found to be 2.8% (in comparing with deionized water) at ϕ = 1% and Re = 15,000, while the minimum gain in the heat was found to be 0.93% at ϕ = 0.2% and Re = 5,000. Furthermore, it was noted that the excessive increase in CuO–Cu nanoparticle concentration causes more pumping power consumption. Moreover, the CuO–Cu nanoparticles residual layer was found to be formed at a high CuO–Cu concentration, which acts as an insulation layer that hinders the heat exchange. It was also found that the threshold of nozzle-to-plate spacing is H = 4, before which, the heat gain is positive, and negative plummet after.

ملخص البحث :

A propeller generates lift in the direction of revolution, similar to a revolving wing. Many previous propeller optimization techniques exist; nevertheless, they often find the optimal thrust coefficient at a constant power coefficient and vice versa. Using two types of algorithms, the genetic algorithm (GA), and the ant colony algorithm (ACO), and comparing with each other, this study will discover the optimal value of the thrust coefficient and the power coefficient combined to obtain the optimum value of the thrust and the lowest value of the power at the same time. A Simple Blade Element Theory Blade served as the foundation for all assumptions. This article examined over 80 various designs, brands, and types of propellers in a 2-blade configuration with diameters ranging from 2.5 to 19 inches and varying pitch values. The data for the baseline propeller was obtained from the UIUC Propeller Database. The inputs for the optimization are the propeller type, diameter, pitch angle, rotational speed, thrust coefficient, and power coefficient. The results show that by determining the factor of interest in the thrust coefficient (FITC), the algorithm can find the optimal propeller specifications. When the (FITC) is 100%, the algorithm will ignore the effect of the power coefficient and vice versa. In the instance (FITC) is 100 percent, the genetic algorithm performed much better than the ant colony algorithm (ACO). But the Ant colony algorithm is more accurate than the genetic algorithm.

ملخص البحث :

The present paper is based on the influence of addition of CuO, ZnO and CuO-ZnO nanoparticles on the dynamic viscosity of SAE 40 engine oil. Samples were prepared of varying percentage of nanoparticles in SAE 40 engine oil (0.02, 0.04. 0.06, 0.08 and 0.1 vol. %). The Experimental results show that both nanoparticles of CuO, ZnO and CuO-ZnO as additives in engine oil at various mixing percentage have higher dynamic viscosity property than the pure engine oil. Also dynamic viscosity of nanoparticles with different concentrations in engine oil gives an effective functionality of engine oil. The measured dynamic viscosities with all parameters affected type of nanoparticles and volume factions were used as inputs to the artificial neural network system to modeling the dynamic viscosity. And This join with Renewable energies investments and methods of utilization and diversification. The ANN model has highly coincided with the experimental results up to 1.5%.

ملخص البحث :

UAVs are designed to create lift in the same direction as the rotation axis, hence propellers are one of the most basic components of propulsion. Although several previous propeller optimization techniques have been developed, they usually find the optimal thrust coefficient at a constant power coefficient and vice versa. This research will combine the optimal values of the thrust coefficient and the power coefficient to find the optimum thrust and the lowest power at the same time. A Simple Blade Element Theory Blade served as the foundation for all assumptions. This article examined over 80 various designs, brands, and types of propellers in a two-blade configuration with diameters ranging from 2.5 to 19 inches and varying pitch values. The data for the baseline propeller was obtained from the UIUC Propeller Database. The inputs for the optimization are the propeller type, diameter, pitch angle, rotational speed, thrust coefficient, and power coefficient. The results show that by determining the factor of interest in the thrust coefficient and the power coefficient, the algorithm can find the optimal propeller specifications. When the factor of interest in the thrust coefficient is 100%, the algorithm will ignore the effect of the power coefficient and vice versa.