A new eddy viscosity equation was formulated from assumption of turbulence length scale equation and specific dissipation ratio equation. Then, a set of turbulence model equations for the turbulent kinetic energy ${kappa}$, the viscosity ${ u}_t$, and the intermittency factor ${gamma}$ is proposed by considering the entrainment effect. Closure coefficients are determined by experimental data and resorting to numerical optimization. Present model has been applied to compute four representative cases of free shear flows and successfully compared with experimental data. In particular, the spreading rate, the centreline mean velocity and the profiles of intermittency are calculated with improved accuracy. Also, the proposed ${ u}_t-{kappa}-{gamma}$ model was applied to channel flow by considering the wall effect and the results show good agreements with the Direct Numerical Simulation data.