Some considerations on frictional losses evaluation of a water flow in microtubes

In the present paper numerical modeling of a water flow through microtubes was made in order to analyze the behavior of the Poiseuille constant for the case of heating fluid flow inside the microtube. The microtube from the experimental research presented in [D. Lelea, S. Nishio, K. Takano, International Journal of Heat and Mass Transfer 47, pp. 2817–2830 (2004). (Journal Article)] was used as a model. The length to diameter ratio of the tube was very large (L/Di = 1200), and a tube diameter was Di = 0.5 mm. Only a portion of the tube was heated with a Joule heating and the heating length was Lh = 250 mm. The working fluid was distilled water and a laminar regime is considered Re < 800. The input power was 2 W.