Sound speed in pure water. Bilaniuk & Wong 148 point equation
Mathematical definition
$$\boxed{C\left( T \right) = {k_0} + {k_1}T + {k_2}{T^2} + {k_3}{T^3} + {k_4}{T^4} + {k_5}{T^5}}$$
| Notation | Description | Units | Limits |
|---|---|---|---|
| $C$ | sound speed | $\text{m/s}$ | |
| $T$ | temperature | $^{\circ}\text{C}$ | $0 < T < 100$ |
| Coefficient | Value |
|---|---|
| $k_{0}$ | $+1.40238744 \times 10^{3}$ |
| $k_{1}$ | $+5.03836171$ |
| $k_{2}$ | $-5.81172916 \times 10^{-2}$ |
| $k_{3}$ | $+3.34638117 \times 10^{-4}$ |
| $k_{4}$ | $-1.48259672 \times 10^{-6}$ |
| $k_{5}$ | $+3.16585020 \times 10^{-9}$ |
Octave/Matlab implementation
function C = sound_speed_water_bilaniuk_148(T)
% Inputs
% T: temperature \ degree Celsius \ 0 < T < 100
% Outputs
% C: speed of sound in pure water \ m/s
k0 = +1.40238744e+3;
k1 = +5.03836171e+0;
k2 = -5.81172916e-2;
k3 = +3.34638117e-4;
k4 = -1.48259672e-6;
k5 = +3.16585020e-9;
C = k0*(T.^0) + k1*(T.^1) + k2*(T.^2) ...
+ k3*(T.^3) + k4*(T.^4) + k5*(T.^5);
end
Computational examples

References
- Bilaniuk, Nykolai; Wong, George SK, "Speed of sound in pure water as a function of temperature", 1993
- Bilaniuk, Nykolai; Wong, George SK, "Erratum: Speed of sound in pure water as a function of temperature [J. Acoust. Soc. Am. 93, 1609–1612 (1993)]", 1996