محمد آموزگار کلاتی

Traditional dhow has been used for years in Iran and other countries in the Persian Gulf and Oman Sea for the transportation of goods and fishing. Today, these vessels are still operational in Iran and play an important role economically. The construction of these vessels is always done traditionally and no scientific research has been done on its design. In the present study, the hydrodynamic resistance, and motions of a dhow model in the towing tank have been investigated experimentally. A model with 95 cm long was made from a real dhow with a length of 21.1 meters and tested in the NIMALA towing tank. Also, the resistance of the dhow model has been calculated using the Holtrop method. The results show that with the increase in speed, the trim of the model increases and reaches 6.8 degrees at a speed of 1.5 m/s. Also, increasing the speed increases the sinkage of the model and at high speeds, the sinkage increases by 2 cm. At the design speed (1.1 m/s), the resistance of the dhow model is 2.476 N, and when the speed increases to 1.5 m/s, the resistance increases sharply and reaches 15.62 N. Also, the results show that the Holtrop method has an acceptable accuracy compared to the experimental results, and this method can be used, in addition to commercial ships, to estimate the resistance of vessels with special bodies such as dhows.