please help me identify this model. Thank you
Both the Sopwith Camel and the Nieuport 11 mentioned elsewhere had rotary engines with a rounded cowling, but the model in the photograph appears to have a square cowling. This suggests it might be a Royal Aircraft Factory S.E.5 or S.E.5a which had a V8 engine.
This particular model appears to have ailerons on the lower wing only, and they are much wider in span and narrower in chord than the ailerons typical of aircraft of this era. This strongly suggests that this is a radio-controlled flying model, and that extreme scale accuracy was not of utmost importance to the builder. This observation may bear strongly on whether or not potential candidates should be eliminated based on various small (or large) differences from the model. The SE-5a in particular comes to mind, and differs from the actual model in the photo in the question in all the following areas--
Model has wide-span, narrow chord, ailerons, on lower wing only, as noted above.
Model lacks an axle connecting the two wheels.
On the model, a close look at the geometry of the apparent visual gap (i.e. as seen from that particular viewing angle) between the TE of the bottom wing and the LE of the top wing shows a wedged-shape gap that indicates a difference in sweep (more on the top wing), or a difference in dihedral angle (more on the top wing), or both.
Based on point #1, it seems reasonable to suggest that points 2 and 3 may simply have resulted from the model builder's lack of interest in extreme accuracy, and that the aircraft may well be a representation of an SE-5a. (If so, the wings of the model are undoubtedly all unswept, like the original, and point #3 arises from more dihedral in the model in the top wing than the bottom wing.)
Point #2 in particular may be simply an accommodation to the practicalities of operating a model plane off grass fields or other "rough" surfaces.