RLOF vs WRLOF

Binary separation = 7 AU

Temperature = 2000 K

Primary mass = 0.8 AU with alpha = 0.1723 that is, primary star behave like an 0.1379 solar mass star. This is presumably due to radiation pressure on dust grains (so the temperature should be like 1500 K)

I am not sure about the mass loss rate of the primary star.

Secondary accrete gas with initial mass of 0.5 solar mass

First picture shows the mass gain of the secondary and the separation decrease of the two stars

​midplane

This gif file is the mid plane density plot of the whole simulation.

People should not take above result too seriously. Many things, for example, mass conserved primary star, self-consistent boundary condition of the primary star, tidal effect and tidal force, non-isothermal situation, should be taken into consideration.

The following are simulations with mass conserved primary.

Red line is the theoretical angular momentum computed from the instantaneous separation (that is, the blue line) of the two stars and their corresponding mass. It is calculated by:

Green line is the result of angular momentum from AstroBEAR.

Initial separation is 4 AU, primary mass = 0.8 solar mass with alpha = 0.1723, secondary is 0.5 solar mass. Gas temperature is 1500 K.

The orbit changed to elliptical one since I turn on accretion and mass conservation mechanism suddenly, so it serves as a perturbation. Distance, theoretical angular momentum and computational angular momentum synchronizes afterward. We can see that the mean slope of green line is lower than the red line. That is to say, part of the orbital energy is changed to some other kind of energy. Since the simulation is isothermal, it can only be transformed into gas's kinetic energy or its gravitational potential energy.

I forgot to deduct momentum of the primary in simulation, that is, its momentum is not conserved, that is why angular momentum is increasing.

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