Water flows through a tube of diameter $25$ $mm$ at an average velocity of $1.0$ $m/s$. The properties of water are $\rho$=$1000$ $kg/m^3$, $\mu$=$7.25 ×10^{−4}$ $N.s/m^2$, $k$=$0.625$ $W/m.K$, $P_r$ = $4.85$. Using $N_\mu =0.023R_e^{0.8}P_r^{0.4}$ , the convective heat transfer coefficient (in $W/m^2.K$) is _______