We have implemented prescriptions for modelling pulsars in the rapid binary population synthesis code COMPAS .
We perform a detailed analysis of the double neutron star ( DNS ) population , accounting for radio survey selection effects .
The surface magnetic field decay timescale ( { \approx } 1000 Myr ) and mass scale ( { \approx } 0.02 M _ { \odot } ) are the dominant uncertainties in our model .
Mass accretion during common envelope evolution plays a non-trivial role in recycling pulsars .
We find a best-fit model that is in broad agreement with the observed Galactic DNS population .
Though the pulsar parameters ( period and period derivative ) are strongly biased by radio selection effects , the observed orbital parameters ( orbital period and eccentricity ) closely represent the intrinsic distributions .
The number of radio observable DNSs in the Milky Way at present is \approx 2500 in our model , only \approx 10 % of the predicted total number of DNSs in the galaxy .
Using our model calibrated to the Galactic DNS population , we make predictions for DNS mergers observed in gravitational waves .
The DNS chirp mass distribution varies from \approx 1.1M _ { \odot } to \approx 2.1M _ { \odot } and median is obtained to be 1.14 M _ { \mathrm { \odot } } .
The expected effective spin \chi _ { \mathrm { eff } } for isolated DNSs is \lesssim 0.03 from our model .
We predict that \approx 34 % of the current Galactic isolated DNSs will merge within a Hubble time , and have a median total mass of 2.7 M _ { \mathrm { \odot } } .
Finally , we discuss implications for fast radio bursts and post-merger remnant gravitational-waves .