Ошибка floating point exception во Fluent

Добрый день.

Моделирую вихревую трубу. Задаю давление и температуру на входе и выходах. density-based решатель. модель турбулентности k-epilson standard

в качестве газа был выбран метан с плотностью, изменяющейся по закону сжимаемого идеального газа

выдает ошибку floating point exception. Подскажите, пожалуйста, в чем может быть причина. Спасибо

writing rp variables ... Done.

writing domain variables ... Done.

writing solid (type fluid) (mixture) ... Done.

writing outlet2 (type pressure-outlet) (mixture) ... Done.

writing outlet1 (type pressure-outlet) (mixture) ... Done.

writing inlet (type pressure-inlet) (mixture) ... Done.

writing interior-solid (type interior) (mixture) ... Done.

writing wall (type wall) (mixture) ... Done.

writing zones map name-id ... Done.

iter continuity x-velocity y-velocity z-velocity energy k epsilon time/iter

49 1.2341e+37 1.4160e+71 9.8502e+70 6.5281e+70 3.2732e+104 4.5918e+29 0.0000e+00 4:21:46 1000

Warning: Invalid cp (0.000000e+00 J/kgK) for methane at temperature -1.#IND00 K

reversed flow in 319 faces on pressure-outlet 6.

reversed flow in 670 faces on pressure-outlet 7.

Divergence detected in AMG solver: k

Divergence detected in AMG solver: epsilon

Divergence detected in AMG solver: k

Divergence detected in AMG solver: epsilon

Divergence detected in AMG solver: k

Divergence detected in AMG solver: epsilon

Divergence detected in AMG solver: k

Divergence detected in AMG solver: epsilon

Error at host: floating point exception

Error at Node 0: floating point exception