{HEAD ~ The airfoil effect} generated by {TAIL ~ the arcuate shape} 16 is effective to reduce the friction between fibre fleece 4 and trough bottom 9 
generated by
{ HEAD ~ The airfoil effect } generated by { TAIL ~ the arcuate shape } 16 is effective to reduce the friction between fibre fleece 4 and trough bottom 9
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH