vitesse des fluides dans les conduits et pertes de chargevitesse des fluides dans les conduits et pertes de charge

The pressure generated by the change in velocity (dynamic pressure) is reversible:If for a given flow a converging cone accelerates the fluid the pressure decreases (see Bernoulli), but if another diverging cone, positioned downstream, slows down the fluid to its original speed, the balance of dynamic pressure is zero:

 

See energies pressure

velocity of the fluids in the pipes and pressure drop

aerodynamics hydrodynamics relative speed

 

different speeds for the same duct section

*maximum speed is calculated as twice the average speed.

We actually find different rates for the same pipe section. To simplify the calculations we use the average speed:

velocity in pipes

The average speed is based on the relationship:

volume flow (m3 / s) / section area (m²) = average velocity (m / s)

The average speed in the case of a constant flow leads to the continuity equation

The maximum velocity of a fluid in a conduit is determined by the pressure loss causes. This head loss "eligible" for the duct is not noisy or does not generate additional cost of operation (energy pumping) must be less than 20 mm / m load per unit length loss.

To correctly sizing the diameter of an hydraulic or aerailic pipe according to its flow rate, you can use the sizing tool: sizing pipe

he average speed and speed at the center pipe in Mecaflux Standard:velocity in pipes

The minimum velocity of a fluid in a pipe, is often determined by the sedimentation velocity of particles suspended in the fluid. The minimum speed is also determined by the price of the pipes and their installation. Indeed a slow speed brings low operating costs and pumping, but large pipe diameters, ensuring that low speed are expensive to purchase and installation. We consider in practice, that a loss of load per unit length of 15 mm / m, is a good compromise between duct diameter and energy expenditure.

An interface to aid design of aeraulic ducts or hydraulic is integrated mecaflux. So the control of operating / plant cost.

You can choose to enter a speed or flow rate parameter in Mecaflux standard to calculate the Major head loss:

velocity in pipedetailed input box mecaflux velocity parameter.

 

charge hydrostatique derive aerodynamique hydrodynamique construire aile foil construire eolienne dimensionner conduits fumée carene dirigeable construire helice propulsion derive aerodynamique hydrodynamique frottement sur une surface de coque trainée resistance au vent trainée resistance au vent construire eolienne trainée resistance au vent conception helice bateaux derive aerodynamique hydrodynamique carene dirigeable frottement sur une surface de coque construire aile foil construire aile foil conception hydrolienne calcul voile frottement sur une surface de coque trainée resistance au vent calcul voile construire aile foil construire eolienne construire helice propulsion aeraulique aspiration air systemes ventilation aeration pertes charges vannes debit et pression conduits pompes et ventilateurs vidange reservoir construire aile foil Logiciels de la suite Mecaflux Forces sur des objets géometriques dans un courant de fluide ramification et boucles réseaux dimensionner conduits fumée calcul systemes réseaux fluides gaz liquides helice a vitesse nulle sustentation resistance aerodynamique vehicules calcul debit rivierre helice de captage turbine Kaplan hydroelectrique charge hydrostatique carene dirigeable construire helice propulsion derive aerodynamique hydrodynamique