Free Engineering Simulation Tutorial - Opensource Software & Simulation Guides

Undersize a pipe and your pump strains, your energy bill climbs, and the flow never reaches the far end with enough pressure. Oversize it and you've wasted money on material forever. The number that decides it all is pressure drop — the energy a fluid loses to friction as it travels through a pipe or duct. The gold-standard way to calculate it is the Darcy-Weisbach equation , and this guide gives you a free calculator that does the hard part — the friction factor via the Colebrook-White and Swamee-Jain equations — automatically and accurately. Figure 1. As fluid flows through a pipe, friction with the walls steadily drains its pressure from P₁ to P₂. The Darcy-Weisbach equation quantifies exactly how much is lost. Table of Contents The Pressure Drop / Head Loss Calculator What Are Head Loss & Pressure Drop? The Darcy-Weisbach Equation The Friction Factor (the Hard Part) Colebrook-White vs Swamee-Jain Pipe Roughness Values ...

Your CFD simulation was running fine — then the residuals exploded to infinity and everything turned to NaN. Nine times out of ten, the culprit is a time step that's too large, violating the CFL condition . The Courant–Friedrichs–Lewy number is the single most important control on the stability of any transient (time-marching) simulation, and getting it right is the difference between a clean run and a wasted afternoon. This guide gives you a free CFL calculator (validated against the standard formulas), explains the condition in plain language, and shows you exactly how to choose a stable, efficient time step. Figure 1. The Courant number measures how far the flow travels per time step relative to the cell size. Keep it below 1 (explicit solvers) and the simulation stays stable; exceed it and the solution diverges. Table of Contents The CFL / Courant Number Calculator What Is the CFL / Courant Number? The CFL Stability Condition The Formula...