A study of the effects of the transfer of momentum of the shocked solar wind to the Venus ionosphere near the terminator region is presented. It is shown that the deficiency of momentum flux within the velocity boundary layer in the ionsheath is comparable to the momentum flux present in the upper ionosphere near the terminator. Using the observed concentration of planetary 0+ ions in the wake it is also shown that mass loading processes are not sufficient to account for the loss of momentum flux above the ionopause and that, instead, an efficient coupling must exist between the plasma above and below that boundary. With reasonable values of the thickness and length of the velocity boundary layer it is possible to estimate an effective viscosity coefficient of the flow and the energy released through viscous dissipation. The results indicate that a column integrated energy deposition of the order of 10-2 ergs cm-2 sec-1 can be predicted near the terminator. This number is comparable to that required to heat up the nightside ionosphere as assumed in the modeling studies of Knudsen et al (1979), Cravens et al (1980), Hoegy et al (1980), and Merritt and Thompson (1980).