This work, carried out in the laboratory of Multiphase Thermal-Fluid Dynamics at Energy Department of Politecnico di Milano, presents the results of an experimental campaign aiming at the characterization of air-water-foam flows in a horizontal pipe. The goal is the measurement and analysis of pressure drop and the characterization of the air-water-foam flow. The proposed analysis can be considered an integration of the works by Colombo et al., Fasani and Pari. In particular, the analysis is focused on higher gas and liquid superficial velocity ranges with respect to the previous studies. Firstly, air-water flow without surfactant was studied for velocity ranges between 2.79 < JG < 8.34 m/s and 0.12 < JL < 0.24 m/s. Pressure drops were measured and pressure gradients were computed to set a reference frame. Five different models were implemented: Lockhart-Martinelli, Müller-Steinhagen-Heck, Taitel-Dukler, Dukler and Beattie-Whalley. Then, air-water-surfactant flow was studied with the identification of two flow regimes: an intermittent plug flow at the lowest superficial gas velocities and a stratified-wavy flow for the rest of the conditions; the transition occurs in the range of JG = 3.15 - 4.63 m/s. Subsequently, pressure drops were empirically measured and the gradients were computed and compared with the values obtained for the reference case of air-water flow. Finally they were integrated with the results obtained in the previous works.
Questo lavoro, svolto presso il laboratorio di termofluidodinamica multifase del Dipartimento di Energia del Politecnico di Milano, presenta i risultati di una campagna sperimentale per la caratterizzazione di un flusso bifase aria-acqua in tubi orizzontali in presenza di tensioattivi, con conseguente generazione di schiuma. L’obiettivo di questo lavoro è la misura e conseguente analisi delle cadute di pressione e caratterizzazione del flusso aria-acqua-tensioattivo. L’analisi proposta è considerabile una integrazione dei lavori di Colombo et al., Fasani e Pari. In particolare, l’analisi si è concentrata su intervalli di velocità superficiali maggiori rispetto a quelli precedentemente analizzati. In primo luogo, è stato studiato il flusso aria-acqua senza tensioattivo per velocità superficiali di gas e liquido comprese tra 2.79 < JG < 8.34 m/s e 0.12 < JL < 0.24 m/s: sono state misurate le cadute di pressione e i gradienti di pressione per fissare il quadro di riferimento. Diversi modelli sono stati implementati, quali Lockhart-Martinelli, Müller-Steinhagen-Heck, Taitel-Dukler, Dukler e Beattie-Whalley. Successivamente, è stato studiato il flusso aria-liquido-schiuma: sono stati osservati due principali regimi di moto, un regime a plug alle più basse velocità del gas e un regime stratificato-ondoso a velocità più elevate. La transizione tra questi due moti avviene nell’intervallo JG = 3.15 - 4.63 m/s. Le cadute di pressione sono state misurate sperimentalmente e i gradienti calcolati. Infine, tutti i valori sono stati confrontati con i risultati ottenuti nel caso del flusso aria-acqua e integrati con i risultati ottenuti nei precedenti lavori.
Flow pattern characterization and pressure drop measurements of foamy two-phase flows
Peruch, Matteo
2020/2021
Abstract
This work, carried out in the laboratory of Multiphase Thermal-Fluid Dynamics at Energy Department of Politecnico di Milano, presents the results of an experimental campaign aiming at the characterization of air-water-foam flows in a horizontal pipe. The goal is the measurement and analysis of pressure drop and the characterization of the air-water-foam flow. The proposed analysis can be considered an integration of the works by Colombo et al., Fasani and Pari. In particular, the analysis is focused on higher gas and liquid superficial velocity ranges with respect to the previous studies. Firstly, air-water flow without surfactant was studied for velocity ranges between 2.79 < JG < 8.34 m/s and 0.12 < JL < 0.24 m/s. Pressure drops were measured and pressure gradients were computed to set a reference frame. Five different models were implemented: Lockhart-Martinelli, Müller-Steinhagen-Heck, Taitel-Dukler, Dukler and Beattie-Whalley. Then, air-water-surfactant flow was studied with the identification of two flow regimes: an intermittent plug flow at the lowest superficial gas velocities and a stratified-wavy flow for the rest of the conditions; the transition occurs in the range of JG = 3.15 - 4.63 m/s. Subsequently, pressure drops were empirically measured and the gradients were computed and compared with the values obtained for the reference case of air-water flow. Finally they were integrated with the results obtained in the previous works.| File | Dimensione | Formato | |
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https://hdl.handle.net/10589/173796