In this research, the synthesis of structurally important antioxidants 7-Hydroxy-4-Methyl Coumarin (C1) and 4-Hydroxy Coumarin derivatives was conducted. Coumarin was modified by various reaction steps for the production of target compounds. Different spectroscopic techniques characterized molecular structures FT-IR ,NMR. Antioxidant activity was carried out against 1,1diphenyl-2-picrylhydrazyl (DPPH) in vitro spectrophometric assays. Compared to ascorbic acid, all compounds exhibited high antioxidant efficiency. Among compounds, Compound 9 performance was considered to be the highest (92%), followed by compounds 8 and 10 (90%). Ascorbic acid has been used as a standard drug with inhibition of the percentage 90.5%.

Fluid-structure interaction method is performed to predict the dynamic characteristics of axial fan system. A fluid-structure interface physical environment method (monolithic method) is used to couple the fluid flow solver with the structural solver. The integration of the three-dimensional Navier-Stokes equations is performed in the time Doman, simultaneously to the integration of the three dimensional structural model. The aerodynamic loads are transfer from the flow to structure and the coupling step is repeated within each time step, until the flow solution and the structural solution have converged to yield a coupled solution of the aeroelastic set of equations. Finite element method is applied to solve numerically the Navier-Stockes equations coupled with the structural equations The first ten eigenvalue (natural frequency), the first ten eigenvector (mode shape) and effective stress for each part of a rotor system and complete system assembly are predicted. The validity of the predicted dynamic characteristics of duct fan system was confirmed experimentally by investigating geometrically similar fan system test rig. Good agreement of dynamic characteristics is observed between experimental and numerical results.