Loading...
Please wait, while we are loading the content...
Similar Documents
Evaluation of an active clearance control system concept (Document No: 20080002270)
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Steinetz, Bruce M. DeCastro, Jonathan A. Oswald, Jay Lattime, Scott B. Melcher, Kevin J. Taylor, Shawn |
| Copyright Year | 2005 |
| Description | Reducing blade tip clearances through active tip clearance control in the high pressure turbine can lead to significant reductions in emissions and specific fuel consumption as well as dramatic improvements in operating efficiency and increased service life. Current engines employ scheduled cooling of the outer case flanges to reduce high pressure turbine tip clearances during cruise conditions. These systems have relatively slow response and do not use clearance measurement, thereby forcing cold build clearances to set the minimum clearances at extreme operating conditions (e.g., takeoff, reburst) and not allowing cruise clearances to be minimized due to the possibility of throttle transients (e.g., step change in altitude). In an effort to improve upon current thermal methods, a first generation mechanically-actuated active clearance control (ACC) system has been designed and fabricated. The system utilizes independent actuators, a segmented shroud structure, and clearance measurement feedback to provide fast and precise active clearance control throughout engine operation. Ambient temperature performance tests of this first generation ACC system assessed individual seal component leakage rates and both static and dynamic overall system leakage rates. The ability of the nine electric stepper motors to control the position of the seal carriers in both open- and closed-loop control modes for single and multiple cycles was investigated. The ability of the system to follow simulated engine clearance transients in closed-loop mode showed the system was able to track clearances to within a tight tolerance ( 0.001 in. error). |
| File Size | 4632392 |
| Page Count | 21 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_20080002270 |
| Archival Resource Key | ark:/13960/t36160p8x |
| Language | English |
| Publisher Date | 2005-11-01 |
| Access Restriction | Open |
| Subject Keyword | Aircraft Propulsion And Power Service Life Blade Tips Seals Stoppers Turbine Blades Fuel Consumption Clearances Active Control Turbines High Pressure Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Technical Report |
