Formula Symbols - D

Written by Jerry Ratzlaff on . Posted in Nomenclature & Symbols for Engineering, Mathematics, and Science

For other symbols see:  A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - Q - R - S - T - U - V - W - X - Y - Z

SymbolGreek SymbolDefinitionUSMetric
\(\delta \;,\; \lambda\) delta , lambda dampening coefficient - -
\(C_f \;,\; f_D\) - Darcy friction factor dimensionless number dimensionless number
\(Da\) - Darcy's law - -
\(Da\) - Darcy number dimensionless number dimensionless number
\(DW\) - Darcy-Weisbach equation dimensionless number dimensionless number
\(De\) - Deborah number dimensionless number dimensionless number
\(w_d\) - Debye angular frequency - -
\(q_d\) - Debye angular wave number - -
\(\lambda_d\) lambda Debye length - -
\(\Theta_d\) Theta Debye temperature - -
\(D\) - Debye-Waller factor - -
\(\lambda\) lambda decay constant - -
\(d\) - deceleration \(ft\;/\;sec^2\) \(m\;/\;s^2\)
\(d\) - deflection - -
\(\delta\) delta deformation \(ft\) \(m\)
\(x\) - degree of ionization - -
\(\mu\) mu degree of saturation - -
\(F\) - degrees of freedom - -
\(\rho\) rho density \(lbm\;/\;ft^3\) \(kg\;/\;m^3\)
\(\rho_f\) rho density (fluid) \(lbm\;/\;ft^3\) \(kg\;/\;m^3\)
\(N_e \;,\; \rho\) rho density of state - -
\(z\) - depth \(ft\) \(m\)
\(\partial\) partial derivative (rate of change) - -
\(d\) - diameter \(ft\) \(m\)
\(P\) - dielectric polarization - -
\(d \;,\; \Delta\) delta differential - -
\(D \;,\; D_n \;,\; D_p\) - diffusion coefficient - -
\(L_n \;,\; L_p\) - diffusion length - -
\(\alpha\) alpha diffusivity \(ft^2\;/\;hr\) \(m^2\;/\;s\)
\(a \;,\; b\) - dimension \(in\) \(m\)
\(n\) - dimensionless exponent - -
\(K\) - dimensionless factor - -
\(N\) - dimensionless number - -
\(d \;,\; \vec{d} \;,\; s\) - displacement \(ft\) \(m\)
\( \vec{D}\) - displacement current - -
\(\psi \;,\; \delta\) psi , delta dissipation factor - -
\(E_d\) - dissociation energy - -
\(\delta \) delta displacement \(ft\) \(m\)
\(d \;,\; l \;,\; x \;,\; y\) - distance \(ft\) \(m\)
\(s\) - distance along cable \(ft\) \(m\)
\(a\) - distance to lowest cable point \(ft\) \(m\)
\(w\) - distributed load \(lbf \;/\; ft\) \(N \;/\; m\)
\(E_d\) - donor ionization energy - -
\(D\) - draft \(in \cdot wg\) kPa
\(C_d\) - drag coefficient dimensionless number dimensionless number
\(F_d\) - drag force - -
\(v_{dr}\) - drift velocity - -
\(\zeta\) zeta dryness fraction - -
\(Du\) - Dukhin number dimensionless number dimensionless number
\(Q \;,\; q\) - dynamic pressure - -
\(a\) - dynamic speed constant \(ft \;/\; min\) -
\(\mu \;,\; \eta\) mu (used in mechanical), eta (used in chemical) dynamic viscosity \(lbf-sec\;/\;ft^2\) \(Pa\cdot s\)