Preface Far Eastern Workshop on Computational Technologies and Intelligent Systems - 2021 continues traditions of the Far Eastern School-Seminar in honour of academician E. V. Zolotov that takes its origin in 1981 and took place on the Japan Sea shore. In 1990-th and 2000-th Far Eastern School-Seminar became international and obtained honored popularity not only in the Russian Far East and in the European Russia but also abroad. Up to 200 scientists participated these arrangement including delegations from Japan, Ukraine, Baltic states, Sweden and Russian cities Moscow, Novosibirsk, Kazan, Yekaterinburg, Vladivostok, Khabarovsk. Present conference is the base for presentation and discussion of recent scientific results in computer sciences and it associates different generations of specialist in mathematics and informatics. In this year, our Workshop was held on March, 2-3, 2021 and virtually for the first time because of objective reason. Speakers from different Russian cities Khabarovsk, Vladivostok, Kazan, Moscow and Rostov-on-Don – took the part of the Workshop. Present volume includes the best papers from the Computational technologies section. These papers represent creation of mathematical models and computational technologies for theirs analysis on the computer clusters. Subject of papers is various and includes mesh and hybrid methods for computation of mathematical models with singularity in mechanics of fracture, electrodynamics and hydrodynamics with peculiarity, medicine and engineering. For more information, see Far Eastern Workshop on Computational Technologies and Intelligent Systems - 2021 website at http://ctis2021.ccfebras.ru/index.html Viktor A. Rukavishnikov Pedro M. Lima Alexander Yu. Chebotarev Andrey E. Kovtanyuk Workshop organizers Program committee Viktor A. Rukavishnikov, chairman, Computing Center FEB RAS, Khabarovsk, Russia Pedro M. Lima, University of Lisbon, Portugal Yury V. Shestopalov, University of Gävle, Sweden Oleg P. Tkachenko, Computing Center FEB RAS, Khabarovsk, Russia Alexander Yu. Chebotarev, Institute for Applied Mathematics FEB RAS, Vladivostok, Russia Andrey E. Kovtanyuk, Far Eastern Federal University, Vladivostok, Russia Organizing committee Viktor A. Rukavishnikov, chairman, Computing Center FEB RAS, Khabarovsk, Russia Yu. V. Ponomarchuk, co-chairman, Far Eastern State Transport University, Khabarovsk, Russia Alexey V. Rukavishnikov, co-chairman, FESTU, Khabarovsk, Russia Oleg P. Tkachenko, Computing Center FEB RAS, Khabarovsk, Russia Andrew O. Mosolapov, secretary, Computing Center FEB RAS, Khabarovsk, Russia Anna S. Ryabokon, Computing Center FEB RAS, Khabarovsk, Russia Artem S. Zubkov, Computing Center FEB RAS, Khabarovsk, Russia Ekaterina I. Zazhechnaya, FESTU, Khabarovsk, Russia