{'fraction_non_alphanumeric': 0.01990049751243781, 'fraction_numerical': 0.0012437810945273632, 'mean_word_length': 4.919117647058823, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Numerical investigation of flow recirculation in a draft tube

A numerical investigation of turbulent flow in a draft tube with and without an opening (slot) in the top of each of its three outlet channels is presented. A commercial CFD code, CFX-5, is used to solve the Reynolds-averaged Navier–Stokes equations and a standard k–e turbulence model with a scalable wall-function. The case for no slots was compared with the cases of three mass flow rates into the slots. The results demonstrate that values of the overall pressure coefficient and velocity head obtained for various slot mass flow rates are not significantly different. The flow into the slots, however, creates different amounts of localised recirculation and backflow in the individual outlet channels formed between the two pier noses.