Инженерия: темы
Гидравлика
Расход, давление, потери напора, трубопроводы и насосы.
9 формул
Таблица формул
| Формула | Запись | Тема | Для чего нужна |
|---|---|---|---|
| Flow rate | $Q = A v$ | Гидравлика | Flow rate is the volume of fluid passing through a cross-section per unit time. For idealized one-dimensional flow, it is the product of area and average velocity. |
| Continuity equation | $A_1 v_1 = A_2 v_2 = Q$ | Гидравлика | For steady incompressible flow in a pipe network or conduit, the mass flow continuity implies that discharge is the same at all sections. |
| Velocity from flow rate | $v = \frac{Q}{A}$ | Гидравлика | If flow rate and flow area are known, this equation yields the average velocity in the section. |
| Pressure head | $h_p = \frac{p}{\rho g}$ | Гидравлика | Pressure head converts absolute pressure to an equivalent water column height, useful for balancing energies in flow systems. |
| Bernoulli equation (basic) | $\frac{p_1}{\rho g} + \frac{v_1^2}{2g} + z_1 = \frac{p_2}{\rho g} + \frac{v_2^2}{2g} + z_2$ | Гидравлика | The basic Bernoulli equation links pressure head, velocity head, and elevation head along a streamline for frictionless, steady, incompressible flow. |
| Reynolds number | $Re = \frac{\rho v D_h}{\mu} = \frac{v D_h}{\nu}$ | Гидравлика | Reynolds number indicates the ratio of inertial to viscous forces in a fluid and is used to determine flow regime. |
| Hydraulic diameter | $D_h = \frac{4A}{P_w}$ | Гидравлика | Hydraulic diameter extends circular-pipe relations to non-circular ducts using equivalent diameter based on wetted area and perimeter. |
| Darcy–Weisbach head loss | $h_f = f\frac{L}{D_h}\frac{v^2}{2g}$ | Гидравлика | The Darcy–Weisbach equation estimates major head loss in fully developed pipe flow using friction factor and geometric ratio. |
| Pump power | $P = \frac{\rho g Q H}{\eta}$ | Гидравлика | Pump input power equals hydraulic power raised by the pump divided by pump efficiency. |