Naval Postgraduate School
Dudley Knox Library
NPS Dudley Knox Library
View Item 
  •   Calhoun Home
  • Theses and Dissertations
  • 1. Thesis and Dissertation Collection, all items
  • View Item
  •   Calhoun Home
  • Theses and Dissertations
  • 1. Thesis and Dissertation Collection, all items
  • View Item
  • How to search in Calhoun
  • My Accounts
  • Ask a Librarian
JavaScript is disabled for your browser. Some features of this site may not work without it.

Browse

All of CalhounCollectionsThis Collection

My Account

LoginRegister

Statistics

Most Popular ItemsStatistics by CountryMost Popular Authors

Unsteady separation point injection for pressure recovery improvement in high subsonic diffusers

Thumbnail
Download
IconADA405746.pdf (5.873Mb)
Download Record
Download to EndNote/RefMan (RIS)
Download to BibTex
Author
McElwain, Brian D.
Date
2002-06
Advisor
Paduano, James D.
Metadata
Show full item record
Abstract
Serpentine inlet ducts on modem tactical aircraft distort the inlet flow and decrease pressure recovery at the aerodynamic interface plane (AIP). Current inlet designs are more aggressive, increasing distortion and decreasing pressure recovery at the AIP. Often the flow separates from the wall of the diffuser, creating most of the distortion and pressure loss in the inlet. Diffuser separation experiments were conducted at high subsonic cruise conditions in a 2D test section. Periodic injection tangential to the flow at the separation point improved downstream pressure recovery. The injection also increased static pressure measured at the test section walls in the separated region. Flow visualization tests indicated that the separation shrinks as the injection mass flow increases. Pressure recovery also increased as injection mass flow increased. The unsteady component of the injection flow remained constant with injection mass flow, indicating that the steady component of the injection enhanced control of the separation. The preliminary conclusion is that the average velocity of the injection flow should be at least equivalent to the velocity of the core flow to maximize pressure recovery. Experiments were also conducted in a one-sixth scale tactical aircraft diffuser at cruise conditions (3.1 lb/sec, maximum M = 0.65). Periodic injection at the separation point improved the pressure recovery at the AIP. The improvement in pressure recovery at the AIP was limited to the area of pressure loss due to the separation in the diffuser. The diffuser has strong secondary flows that also cause losses at the AIP. These secondary flows prevented the injection from restoring pressure recovery as well as it had in the 2D test section. Higher injection mass flows than in the 2D case were required to achieve the same degree of improvement in pressure recovery at the AIP.
Description
This thesis document was issued under the authority of another institution, not NPS. At the time it was written, a copy was added to the NPS Library Collection for reasons not now known. It has been included in the digital archive for its historical value to NPS. Not believed to be a CIVINS (Civilian Institutions) title.
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.
URI
http://hdl.handle.net/10945/11024
Collections
  • 1. Thesis and Dissertation Collection, all items

Related items

Showing items related by title, author, creator and subject.

  • Thumbnail

    Unsteady surface pressure and near-wake hot-wire measurements of a circulation control airfoil. 

    Kail, Karl Aurel IV (Monterey, California. Naval Postgraduate School, 1977-09);
    The large lift coefficient changes attainable with Circulation Control Airfoils through small changes in boundary layer blowing suggest rotary wing cyclic control can be obtained through modulation of the blowing. ...
  • Thumbnail

    Characteristics of a four-nozzle, slotted short mixing stack with shroud, gas eductor system 

    Drucker, Carl John (Monterey, California. Naval Postgraduate School, 1982-03);
    Cold flow tests were conducted on a four nozzle (nozzles tilted at a 15 degree angle) gas educator system to evaluate the system's performance utilizing a short slotted missing stack and two shrouds with diffuser rings. ...
  • Thumbnail

    Study of penetration of a liquid injectant into a supersonic flow 

    Kolpin, M.A.; Horn, K.P.; Reichenbach, R.E. (AIAA, 1968-05);
    A study of normal and lateral spray penetration for small-diameter, high-pressure, liquid jets issuing at an angle to a uniform supersonic stream is reported. The experimental program was carried out in the 4-in. by 4-in. ...
NPS Dudley Knox LibraryDUDLEY KNOX LIBRARY
Feedback

411 Dyer Rd. Bldg. 339
Monterey, CA 93943
circdesk@nps.edu
(831) 656-2947
DSN 756-2947

    Federal Depository Library      


Start Your Research

Research Guides
Academic Writing
Ask a Librarian
Copyright at NPS
Graduate Writing Center
How to Cite
Library Liaisons
Research Tools
Thesis Processing Office

Find & Download

Databases List
Articles, Books & More
NPS Theses
NPS Faculty Publications: Calhoun
Journal Titles
Course Reserves

Use the Library

My Accounts
Request Article or Book
Borrow, Renew, Return
Tech Help
Remote Access
Workshops & Tours

For Faculty & Researchers
For International Students
For Alumni

Print, Copy, Scan, Fax
Rooms & Study Spaces
Floor Map
Computers & Software
Adapters, Lockers & More

Collections

NPS Archive: Calhoun
Restricted Resources
Special Collections & Archives
Federal Depository
Homeland Security Digital Library

About

Hours
Library Staff
About Us
Special Exhibits
Policies
Our Affiliates
Visit Us

NPS-Licensed Resources—Terms & Conditions
Copyright Notice

Naval Postgraduate School

Naval Postgraduate School
1 University Circle, Monterey, CA 93943
Driving Directions | Campus Map

This is an official U.S. Navy Website |  Please read our Privacy Policy Notice  |  FOIA |  Section 508 |  No FEAR Act |  Whistleblower Protection |  Copyright and Accessibility |  Contact Webmaster

Export search results

The export option will allow you to export the current search results of the entered query to a file. Different formats are available for download. To export the items, click on the button corresponding with the preferred download format.

A logged-in user can export up to 15000 items. If you're not logged in, you can export no more than 500 items.

To select a subset of the search results, click "Selective Export" button and make a selection of the items you want to export. The amount of items that can be exported at once is similarly restricted as the full export.

After making a selection, click one of the export format buttons. The amount of items that will be exported is indicated in the bubble next to export format.