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Hot massive stars exhibit strong stellar winds that enrich the surroundinginterstellar medium and affect the stars' evolution. However, the winds areinhomogeneous (clumped) and are difficult to model in radiative transfer codes.To produce more realistic spectra many codes use a volume-filling factorapproach to incorporate the effects of clumping. While this approach isconvenient it is simplistic. We introduce an alternative approach toincorporate clumping by assuming the wind is composed of dense sphericalshells. Using this approach in the radiative transfer code CMFGEN we producesynthetic spectra for AzV83, an O7Iaf+ supergiant located in the SmallMagellanic Cloud. The spectrum of AzV83 is rich in both photospheric and windfeatures, making it an ideal candidate with which to investigate the physicalcharacteristics of stellar winds. Synthetic spectra are compared to the star'sobserved spectrum to better characterize the influence of clumped winds onspectral features, and to better understand the limitations of thevolume-filling factor approach. The approach using spherical shells yieldssimilar wind parameters to those obtained using the volume-filling factorapproach although a slightly higher mass-loss rate is required to fitH$\alpha$. As expected, the interclump medium in the model with shells allowsthe high ionisation resonance transitions of N V and O VI to be fitted using$L_{\rm X-ray}/L_{\rm Bol} \approx 10^{-7}$ which is typically observed for Ostars, and which is a factor of ten lower than needed with the volume-fillingfactor approach.

Using Shell Models to Investigate Clumping in the Wind of the O7Iaf+ Supergiant AzV83