Description of Bleed Schematic

The bleed models simulate a bleed boundary without the need to grid and simulate the bleed plenum on the other side. In the main passage, the properties at the edge of the local boundary layer are given by the Mach number (M_δ), total pressure (p_tδ), and total temperature (T_tδ). The surface through which the bleed passes has a total surface area of A_region and porosity (φ). The actual area of the bleed holes is denoted as A_bleed and the mass flow rate though the holes is denoted by m_bleed or m_holes .

The bleed plenum total pressure and total temperature are denoted as p_{t plenum} and T_{t plenum}. Since the plenum is at a near-stagnation condition, with a Mach number (M) approximately zero, the plenum static pressure (p_plenum) is nearly the same as the plenum total pressure. The plenum chamber has an exit passage of area A_exit and discharge coefficient C_D. The mass flow through the exit is m_exit and the static pressure at the end of the passage is p_exit.

During steady operation, the bleed mass flow rate (m_bleed) must be the same as the mass flow rate through the bleed holes (m_holes) and also the mass flow rate through the plenum exit (m_exit).