ENGG 2230 Lecture Notes - Lecture 7: Sign Convention

• School: University of Guelph
• Department: Engineering
• Course: ENGG 2230
• Professor: Bill Van Heyst

Document Summary

Using the reynolds equation with b=mv and =v: is the sum of forces on the system and must have x,y, and z components, (cid:4666)(cid:1865)(cid:4667)= = (cid:3031)(cid:3031)(cid:3047)(cid:4666) (cid:4667)+ (cid:4666)(cid:1865) (cid:4667)(cid:3042)(cid:3048)(cid:3047: = (cid:3031)(cid:3031)(cid:3047)(cid:4666) (cid:4667), m = av. If the system has one-dimensional inlets and outlets. Forces in solid bodies that protrude through the surface: pressure forces and viscous stresses due to the surrounding fluid. Use cartesian sign convention for fx, fy, vx, and vy. If q is i(cid:374)to the syste(cid:373) the(cid:374) it"s (cid:374)egative, if q is out of the syste(cid:373) the(cid:374) it"s positive. The pressure that acts on a surface is perpendicular to the surface and the vector. If the fluid is steady state: (cid:3051)= (cid:1865) (cid:3051) = (cid:1843)(cid:3051, (cid:3052)= (cid:1865) (cid:3052) = (cid:1843)(cid:3052) Pressure forces the net pressure zero points into the surface: (cid:3043)(cid:3045)(cid:3032)(cid:3046)(cid:3046)= (cid:1842)(cid:4666) (cid:1866)(cid:4667, (cid:3043)(cid:3045)(cid:3032)(cid:3046)(cid:3046)= (cid:1842)(cid:3048)(cid:3032)(cid:4666) (cid:1866)(cid:4667) calculations easier. If pressure is uniform around the surface then the vectors cancel out which makes.