Batman University

About: Batman University is a education organization based out in Batman, Turkey. It is known for research contribution in the topics: Diesel fuel & Diesel engine. The organization has 300 authors who have published 810 publications receiving 10346 citations. The organization is also known as: Batman Üniversitesi.

Improved Manta Ray Foraging Optimization Using Opposition-based Learning for Optimization Problems

Abstract: Manta ray foraging optimization (MRFO) algorithm is a bio-inspired meta-heuristic algorithm. It has been proposed as an alternative optimization approach for real-world engineering problems. However, MRFO is not good at fine-tuning of solutions around optima and suffers from slow convergence speed because of its stochastic nature. It needs to be improved due to latter issues. Therefore, in this study, opposition-based learning (OBL) technique was used together with MRFO in order to obtain an effective structure for optimization problems. The proposed structure has been named as opposition-based Manta ray foraging optimization (OBL-MRFO). In the proposed algorithm, the advantage of OBL in terms of considering the opposite solutions was used to have an algorithm with better performance. The proposed algorithm has been tested on four different benchmark functions such as Sphere, Rosenbrock, Schwefel and Ackley. Statistical analyses were performed through comparing the performance of OBL-MRFO with the other algorithms such as salp swarm algorithm, atom search optimization and original MRFO. The results showed that the proposed algorithm is more effective and has better performance than other algorithms.

Experimental and numerical investigation of thermal characteristics of a novel concentric type tube heat exchanger with turbulators

Abstract: SUMMARY In this study, the heat transfer performance and friction characteristics of a novel concentric tube heat exchanger with different pitches of helical turbulators were investigated experimentally and numerically for a Reynolds number range from 3000 to 14 000. An experimental system was established to obtain experimental data. The numerical simulations were performed by using a three dimensional numerical computation technique, a commercial CFD computer code. Then, the heat transfer performance and friction characteristics of several helical turbulators were compared. The experimental, numerical and empirical correlation results were in a good agreement with each others. As a result, the heat transfer enhancements using turbulators were 2.91, 2.41, 2.18 and 1.99 times better than the smooth tube for pitch distances of p = 20, 40, 60 and 80 mm, respectively. Copyright © 2012 John Wiley & Sons, Ltd.

Increasing single-lap joint strength by adherend curvature-induced residual stresses

Abstract: Single-lap joint (SLJ) geometry is the most widely used type of adhesive joint geometry. In this joint, peel stresses occur at the overlap ends due to load eccentricity and the presence of shear-free adhesive termination surfaces. These peel stresses, along with the transverse tensile stresses which occur along the overlap longitudinal axes, and adhesive shear stresses, ultimately cause joint failure. Obviously, reductions in these stresses should result in higher joint strength and increased load capacity. To this end, we exploited elastic spring-back capability of (steel) metal adherends by initially forming curved segments of varying arc lengths and radii at overlap ends. These adherends with curved-end sections were then bonded in single-lap configuration, simply by applying sufficient bonding pressure to elastically flatten the curved segments to result in typically flat overlap sections subsequent to adhesive cure and the removal of bonding pressure. Since the elastic adherend overlap ends tend to r...

Biodiesel properties of microalgae (Chlorella protothecoides) oil for use in diesel engines

Abstract: In this study, biodiesel was produced from a microalgae oil, chlorella protothecoides, by typical alkali-catalyzed transesterification in conditions such as a 0.75 wt.% KOH of the oil as catalyst, 68°C and 80 min which was agreed as optimal conditions after investigating the effect of KOH concentration, reaction temperature and time at constant molar ratio of 6:1 on the conversion rate and fuel properties. Under these conditions, a 98.6% conversion rate of algae oil to its methyl ester was achieved with ester content higher than 96%. Furthermore, all physicochemical properties met the requirements of international biodiesel standards, EN 14214 and ASTM D 6751, with some remarkable ones such as high cetane number (57.3) and low CFPP (−10°C). The effect of microalgae biodiesel volume fraction in the fuel on the kinematic viscosity, CFPP, lubricity, density, and distillation temperature was also studied. A blending ratio of the algal-biodiesel up to 50% (v/v) was also found in agreement with the stan...