Investigation of helical flow by using tracer technique N. Altınsoy, A.B. Tuğrul, F. Baytaş, N. Baydoğan, N. Karatepe, S. Hacıyakupoğlu and B. Büyük EPJ Web of Conferences, 50 (2013) 01001 Published online: 28 May 2013 DOI: 10.1051/epjconf/20135001001