| Sign In to gain access to subscriptions and/or personal tools. |
Characterizing the Leakage Flow of Braided Fiber SealsDrexel University, Philadelphia, Pennsylvania 19104, U.S.A.
Drexel University, Philadelphia, Pennsylvania 19104, U.S.A.
Drexel University, Philadelphia, Pennsylvania 19104, U.S.A.
NASA Lewis Research Center, Cleveland, Ohio 44135, U.S.A. A new kind of high temperature flexible braided fiber seal has been developed for advanced hypersonic engine applications. Leakage flow experimental observations show that both engine pressure and preload pressure influence leakage flow rate. Al though the Reynolds number is relatively small ( Re < 10), the mass flow rate com parison of air versus helium reveals that the leakage flow is not viscous dominant. The Ergun equation describing flow through porous media is applied to the flow analysis. The two constants in the Ergun equation, designated as the viscous flow constant CL and the inertial flow constant CT, are determined experimentally. For the leakage flow test setup and the seal geometry, test data show that the values of CL and CT vary for different seal fiber architectures. The relative magnitude of the non viscous flow effect can be determined using a dimensionless variable (ReCT/CL). If this variable is much less than 1, the nonviscous flow effect can be neglected. For the seals tested, the ratio of CT/CL is at the range of about 1 to 2 in most cases. Therefore the criterion for the viscous dominant flow is Re < 0.1. Predictions of seal leakage flow using the Ergun equation show good agreement with experimental data of both fluid media, air and helium.
Textile Research Journal, Vol. 64, No. 1,
1-9 (1994) |
|||
 |
|
|
 |
|
Sign In to gain access to subscriptions and/or personal tools.
