Sharif University of Technology Scientia Iranica 1026-3098 22 3 2015 06 01 Rooster Tail Depression by Originating a Modified Transom Stern Form Using a Reynolds Averaged Navier Stokes Solver Rooster Tail Depression by Originating a Modified Transom Stern Form Using a Reynolds Averaged Navier Stokes Solver 765 777 3670 EN Parviz Ghadimi Dept. of Marine technology, Amirkabir University of Technology, Teheran, Iran Abbas Dashtimanesh Dept. of Marine technology, Amirkabir University of Technology, Teheran, Iran Rahim Zamanian Dept. of Marine technology, Amirkabir University of Technology, Teheran, Iran Mohammad A. Feizi Chekab Dept. of Marine technology, Amirkabir University of Technology, Teheran, Iran Seyed Hamid R. Mirhosseini Dept. of Marine technology, Amirkabir University of Technology, Teheran, Iran Journal Article 2014 11 29 The present article relates to a new transom stern form for high speed planing hulls. To depress the intensive transom wave known as “rooster tail”, an innovative form of transom stern is originated. The new form of the transom stern is introduced by cutting the bottom of the hull near the transom stern. To verify the capability of the modified transom stern, a three dimensional RANS solver is used. It is demonstrated that by using the new transom stern shape, the intensive wave behind the transom will be substantially reduced in the range of the parameters under investigation.  In the meantime, it is expected that the radar signature will also be decreased. To study the effect of modified transom at various Froude numbers and different trim angles, a set of numerical experiments are conducted. Three Froude numbers and four trim angles are considered and it is observed that the cutted transom stern has a significant effect on the reduction of height and length (height reduction up to 61% and length reduction up to 63%) of the rooster tail. Additionally, the accuracy of the numerical solutions is validated by comparing them against the results of empirical formula existing in the literature. https://scientiairanica.sharif.edu/article_3670_29c0d3f10f16d5cb19cdd1c95265f1e7.pdf