# Convective heat transfer coefficients

Hi. I'm trying to make a simple model of a condensation based countercurrent heat exchanger where liquid water and steam flows are separated by a conducting wall. I formed the equations as

$$Q = \frac{T_{steam}-T_{water}}{\frac{1}{Ah_{water}}\frac{d}{Ak_{wall}}\frac{1}{Ah_{steam}}} = L\dot{m}$$

where L is the latent heat released by the condensing steam. The trouble is, I don't know the convective heat transfer coefficients. Is there a way to calculate the h-coefficients based on flow velocity or what's the deal with them?