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Comparison of hirs' equation of moody's equation for determining rotordynamic coefficients of annular pressure seals
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Nguyen, Dung T. Nelson, Clayton C. |
| Copyright Year | 1987 |
| Description | The rotordynamic coefficients of an incompressible-flow annular pressure seal were determined using a bulk-flow model in conjunction with two different friction factor relationships. The first, Hirs' equation, assumes the friction factor is a function of Reynolds number only. The second, Moody's equation, approximates Moody's diagram and assumes the friction factor is a function of both Reynolds number and relative roughness. For each value of relative roughness, Hirs' constants were determined so that both equations gave the same magnitude and slope of the friction factor. For smooth seals, both relationships give the same results. For rough seals (e/2 H sub 0 = 0.05) Moody's equation predicts 44% greater direct stiffness, 35% greater cross-coupled stiffness, 19% smaller cross-coupled damping, 59% smaller cross-coupled inertia, and nominally the same direct damping and direct inertia. |
| File Size | 509211 |
| Page Count | 15 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19870012775 |
| Archival Resource Key | ark:/13960/t5s80885c |
| Language | English |
| Publisher Date | 1987-01-01 |
| Access Restriction | Open |
| Subject Keyword | Mechanical Engineering Damping Coefficient of Friction Seals Stoppers Incompressible Flow Cross Coupling Reynolds Number Rotors Roughness Aerodynamic Coefficients Stiffness Annular Flow Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
