Rhyan Edwin, BS Thesis, Dept. of Physics, University of Indonesia, 2010
Simulation and Experiment have been carried out to characterize the propagation of ultrasonic wave in metal to detect metal fracture on inside surface of CNG tube. The simulation is using software Comsol Multiphysics 3.4 based on finite element method. the system is simulated by transmitting waves generated by 4 MHz ultrasonic pulse-beam angle transducer with orientation angle of 70o through the metal wall, and subsequently received by another transducer. Ultrasonic waves transmitted through the metal wall will experience an attenuation effects which is caused by the absorption and wave reflection on a surface due to the difference in accoustic impedance. as a result ultrasonic waves with reduced intensively are received. analyses of the result are done by comparing the intensity of utrasonic wave signal from simulation and experiment received at various conditions of cracks. keywords: CNG, ultrasound waves, acoustic impedance, transducer, cracks.