Reynolds Number • Friction Factor • Pressure Drop • Head Loss — Simulate • Explore • Practice • Quiz
Fluid flow in pipes is a fundamental topic in fluid mechanics and hydraulic engineering. Engineers analyse pipe flow to design efficient piping systems for water supply, oil transport, HVAC systems, and chemical processing. Understanding flow regimes, pressure losses, and velocity distributions is essential for selecting pipe sizes, pump capacities, and ensuring system reliability.
Pipe flow is characterised by the Reynolds number (Re = ρVD/μ), a dimensionless parameter that determines whether flow is laminar (Re < 2300), transitional (2300 < Re < 4000), or turbulent (Re > 4000). Laminar flow exhibits smooth, orderly streamlines with a parabolic velocity profile, while turbulent flow has chaotic eddies and a flatter velocity distribution.
The Darcy-Weisbach equation (hf = f(L/D)(V²/2g)) calculates major head loss due to friction along the pipe length, where f is the Darcy friction factor, L is pipe length, D is diameter, V is mean velocity, and g is gravitational acceleration. For laminar flow, f = 64/Re (Hagen-Poiseuille). For turbulent flow, the Colebrook equation relates f to Reynolds number and relative roughness ε/D. The Moody diagram provides a graphical solution for friction factor across all flow regimes.
Minor losses occur at pipe fittings, bends, valves, expansions, and contractions. These are calculated as hm = K(V²/2g), where K is the loss coefficient specific to each fitting type. The total head loss in a piping system is the sum of major (friction) and minor (fitting) losses.
In Simulate mode, select a fluid type (Water, Oil, Air, or Glycerin), choose a pipe material (Smooth, PVC, Commercial Steel, or Cast Iron), and adjust pipe diameter, length, flow velocity, and number of bends using the sliders. The canvas displays the pipe cross-section with animated velocity profile, pressure gradient, and HGL/EGL lines — all updating in real time. Use presets for common flow scenarios. Switch to Explore mode to study 12 concepts across Flow Basics, Key Equations, and Losses & Friction with worked examples. Practice mode generates random pipe flow problems, and Quiz tests your knowledge with 5 randomised questions.
This simulator is designed for mechanical and civil engineering students, HVAC designers, plumbing engineers, fluid mechanics instructors, and anyone studying pipe flow analysis. It provides visual, hands-on understanding of flow regimes, pressure losses, and energy lines without requiring laboratory equipment or complex software.