  Supergiant fast X-ray transient (SFXT) is a new class of the high mass X-ray
binary that shows short X-ray flares. The physical mechanism of SFXT short
flares is still open for discussion. The accretion process of dense clumps in
stellar wind onto neutron star (NS) has been proposed as the origin of such
short flares. In order to examine the applicability of the clumpy wind
scenario, we focus on the accretion mode that depends on orbital parameters.
Our goal is to impose restrictions on the orbital parameters of SFXT. Assuming
a simple analytic model of clumpy wind, we investigate the condition where the
size of accretion cylinder overcomes the clump size. The allowed parameter
region for SFXT is restricted in a relatively narrow window in $P_{\rm{orb}} -
e$ diagram. Binary systems with large eccentricities ($e \ga 0.4$) and moderate
orbital periods ($P_{\rm{orb}} \sim 10$ d) are prone to show periodic X-ray
outbursts which are characteristic for SFXT. We confirm that systems with a
long orbital period of more than 100 days cannot produce bright X-ray flares in
the simple clumpy wind scenario.
