Düşey borularda su-buhar akışı için iki-fazlı sürtünme çarpanı tarama tablosu

Two-phase steam-water flows are extensively used in many industrial facilities, especially in nuclear power plants. The limits and capacity of these facilities are determined based on some critical parameters of two-phase flows, such as critical heat flux (CHF) and two-phase friction multiplier, and thermophysical properties of the working fluid. Many experimental measurements have been performed to determine the pressure drops and many studies are published in the form of measurement results, as well as correlations and mathematical methods basing on the results of these measurements to determine the two-phase friction multiplier for different flow conditions. However, these studies cover only limited ranges of the flow conditions and the thermophysical properties, such as heat flux (q"), pressure (P), mass flux (G) and actual (dynamic) quality (xa). Also, different results take place for the pressure drops depending on the experimental set-up and conditions,. Additionally, experimental data and correlations do not exist in some cases in the literature, where it is hard to reach the required flow conditions with an experimental set-up in addition to the scarce numbers of data. It becomes widespread to construct and utilize look-up tables (LUTs) for selected critical parameters of the two-phase flows based on some methods, correlations and experimental data and using these LUTs in the computer codes. In this thesis, a two-phase friction multiplier look-up table for two-phase steam-water flows in vertical uniformly heated and adiabatic round tubes has been developed covering the ranges of Heat flux: 0 ≤ q" ≤ 6000 kW/m2 Pressure: 500 ≤ P ≤ 11,000 kPa Mass flux: 500 ≤ G ≤ 10,000 kg/m2 s Actual (flow) quality: 0.0 ≤ xa ≤ 1.0