The Measurement, Modeling and Prediction of Traction for Rocket Propellant 1
Abstract
The bearings used in rocket motor turbopumps are lubricated with the process liquid, no matter whether this is a mineral-based low-viscosity fuel such as RP1, or a cryogenic substance. Thus it is critically important that the rheological properties of the working fluid be known and modeled. Traction tests were performed on RP1, a common kerosene based rocket propellant. Traction data on this fluid are required for purposes of turbopump bearing design, using codes such as SHABERTH. To obtain the traction data, an existing twin disc machine was used, operating under the side slip mode and using elliptical contacts. The range of test variables were: contact peak Hertz stress from 1.0 to 2.0 GPa, disc surface speed from 10 to 50 m/s, fluid inlet temperature from 30 to 70 C, and with a contact aspect ratio of 1.7. The resulting traction curves were reduced to fundamental fluid property parameters using the Johnson and TEvaarwerk traction model. Theoretical traction predictions were performed by back substitution of the fundamental properties into the traction model. Comparison of the predicted with the measured curves gives a high degree of confidence in the correctness of the predicted with the measured curves gives a high degree of confidence in the correctness of the traction model. For purposes of input to the NASA SHABERTH program, the traction model was next used to predict the expected tractio n of RP1 under line contact conditions.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1989
- Accession Number
- ADA227570
Entities
People
- Joseph L. Tevaarwerk