Poor mesh qcuality
 

Hello guys
I am doing simulation of forced convection through a rib-grooved square duct (turbulent flow). So i wanted to use inflation layers on the walls...but as soon as i introduced inflation, my mesh quality gets deteriorated...before using inflation, my skewness was .56.....but after inflation the skewness becomes 1...so can you plz tell how to mesh my duct to get better quality using inflation layers?