Correlations predicting liquid hold-up and pressure gradient in steady-state (nearly) horizontal co-current gas-liquid pipe flow

The liquid hold-up epsilon (L) and pressure gradient (-dP/dx)(Tp) occurring during steady-state (nearly) horizontal co-current gas-liquid pipe flow ha ve been calculated using the general momentum balances for both phases, two different models for the wall shear stresses and 22 different correlations for the interfacial friction factor. The calculated results are compared w ith an experimental database of the University of Amsterdam, consisting of 3981 measurements of gas-liquid pipe flow in three flow regimes, i.e. strat ified, wavy and annular flow, and the following process conditions: pipe di ameters 0.0127 < D-i/m < 0.0953, lengths 11 < L/m < 22, angles of inclinati on -5 < <beta>(T)/degrees < 6 and viscosities 8.52 x 10(-4) < etaL/(Pa.s) < 0.092, densities 996 < rho (L)/(kg m(-3)) < 1220, surface tensions 0.038 < sigma/(Pa.m) < 0.073. The database comprises data of Andristos. Furthermor e, newly acquired experimental data is presented, obtained with a newly con structed experimental gas-liquid flowloop. This data adds to the public dom ain and may be used by other researchers to develop and test newf(i)-relati ons. The authors found that a newly developed f(i) model based on the inter facial wave velocity C, presented in this paper, gives the best simultaneou s prediction of both the liquid hold-up and the pressure gradient. The f(i) model of Andritsos and Hanratty(1) combined with the model for the wall fr iction factors f(G), f(L) of Taitel and Dukler(2) calculates the most accur ate value of the pressure gradient. The f(i) model of Grolman and Fortuin(3 ) combined with the wall ftiction factors f(G), f(L) of Hart et al.(4) calc ulates the most accurate value of the liquid hold-up.