DESIGN OF A WIND-TUNNEL ROLL-DAMPING BALANCE INCORPORATING EXTERNALLY PRESSURIZED GAS BEARINGS OPERATING AT LARGE FILM REYNOLDS NUMBERS
Abstract
A roll damping, wind tunnel balance consisting of journal and thrust gas (N2) lubricated bearings was designed for use in the von Karman Gas Dynamics Facility's continuous flow tunnels at the Arnold Engineering Development Center. The balance was designed to be contained in a space envelope of 2.5 inches in diameter and 8.0 inches long. It was required to support a radial load of 350 pounds located plus or minus 2 inches from the journal bearing center and a thrust load of 150 pounds. In order to meet these specifications, the bearings had to be designed with large gas film Reynolds numbers where the assumptions of laminar flow and negligible inertia of the gas used in lubrication theory may be invalid. An experimental investigation of the bearing resulting from the initial design showed it to have a turbulent gas film which caused an unexpected detrimental effect on load capacity. A more thorough theoretical analysis was conducted to determine the effects of turbulent flow on gas bearing load capacity. Another bearing was designed and fabricated to operate in the laminar flow regime which improved the operating characteristics and was in good agreement with laminar flow theory.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1969
- Accession Number
- AD0694502
Entities
People
- G. E. Burt
Organizations
- Arnold Engineering Development Complex