Performance of an Oswatisch Inlet with Hemispherical Centerbody at Zero Angle of Attack
Abstract
This thesis analyzes the performance of a ramjet with an Oswatisch inlet using a blunt centerbody and compares performance to a baseline ramjet using an inlet with a conical spike at Mach 3.0. Inlet performance as a ratio of inlet tip to nose centerbody ratio, r sub L/r sub n, is developed. The capture streamline for each ratio is determined and the coefficient of additive drag is calculated as a function of r sub L/r sub n. Setting thrust coefficient equal to coefficient of drag, the performance of two ramjets is determined. One ramjet is the baseline with a spike inlet; the other ramjet uses the blunt centerbody. Ramjets and inlets are compared on the basis of specific fuel consumption, excess thrust coefficient and specific thrust. For the ramjet with blunt centerbody, performance parameters were calculated as a function of inlet lip radius to nose centerbody radius. Also compared is the effect of the ratio, r sub L/r sub n, on relative detection range. For both types of ramjets, the detection range is reduced by approximately 66%. Performance of the ramjet with blunt nosed centerbody is severly handicapped due to high additive drag and poor pressure recovery. Specific fuel consumption is approximately 50% greater for the ramjet with the blunt centerbody compared to the ramjet with the spike inlet.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1981
- Accession Number
- ADA107439
Entities
People
- John F. Moran
Organizations
- Naval Postgraduate School