Experimental correlations on critical Reynolds numbers and friction factor in tubes with wire-coil inserts in laminar, transitional and low turbulent flow regimes

摘要

Graphical abstractDisplay OmittedHighlights?23 Wire-coils were tested for: p/d=[0.25–3.37], e/d=[0.071–0.286] and Re=[50–8000].?Wire-coil were categorized with a new dimensionless Transition Shape Parameter.?TSP is able to distinguish three different patterns on transition to turbulence region.?Critical Reynolds and friction factor correlations for all flow regimes are given.AbstractThis paper analyses 23 circular helicoidal wire-coils with different geometric characteristics ranging from: dimensionless pitch p/d=[0.25–3.37], dimensionless thickness e/d=[0.071–0.286] and a Reynolds number interval from