Smooth Transition from Shakura-Sunyaev Disc to Advection-Dominated Accretion Flow

We solve a set of basic equations describing black hole accretion flows using the standard Runge-Kutta method and a bridging formula for the radiative cooling, and show that a smooth transition from an Shakura-Sunyaev disc to an advection-dominated accretion flow is realizable for the high-viscosity case, without the need of involving any extra mechanism of energy transport.