Landing gear noise computations require the calculation of unsteady flow fields around complex geometries. Previous experience gained at Onera established the benefit of unstructured grids in CFD computations on both an academic tandem cylinder case and a real life landing gear (LG) complex geometries. The present study extends previous works to assess the noise generated by two different testing configurations of a subscale simplified model of a Gulfstream nose landing gear, namely the Partially Dressed Closed Cavity Nose Landing Gear (PDCC-NLG). This particular test case is proposed in the framework of the Benchmark for Airframe Noise Computations (BANC) managed by NASA LaRC. The proposed hybrid CAA approach associates two Onera in house codes: one, for the flow solution, relies on a DDES (Delayed Detached Eddy Simulation) method implemented in Onera unstructured flow solver CEDRE and one, for the computation of the far field noise, is based on the Onera code KIM that relies on an integral FW-H (Ffowcs Williams-Hawkings) method. Solutions obtained for the PDCC-NLG model in two different facilities are presented and commented. In particular grid sensitivity is discussed by comparing solutions obtained on two different grids for one configuration.