Energy analysis of propulsion systems for high speed vehicles

1989 ◽  
Author(s):  
PAUL CZYSZ ◽  
S. MURTHY
Keyword(s):  
High Speed ◽  
Energy Analysis ◽  
Propulsion Systems

Direct Outer Ring Cooling of a High Speed Jet Engine Mainshaft Ball Bearing: Experimental Investigation Results

2010 ◽  
Author(s):  
Peter Gloeckner ◽  
Klaus Dullenkopf ◽  
Michael Flouros
Keyword(s):  
Power Dissipation ◽  
High Speed ◽  
Ball Bearing ◽  
Operating Conditions ◽  
Outer Ring ◽  
Outer Diameter ◽  
Propulsion Systems ◽  
Jet Engine ◽  
Power Loss Reduction ◽  
The Impact

Operating conditions in high speed mainshaft ball bearings applied in new aircraft propulsion systems require enhanced bearing designs and materials. Rotational speeds, loads, demands on higher thrust capability, and reliability have increased continuously over the last years. A consequence of these increasing operating conditions are increased bearing temperatures. A state of the art jet engine high speed ball bearing has been modified with an oil channel in the outer diameter of the bearing. This oil channel provides direct cooling of the outer ring. Rig testing under typical flight conditions has been performed to investigate the cooling efficiency of the outer ring oil channel. In this paper the experimental results including bearing temperature distribution, power dissipation, bearing oil pumping and the impact on oil mass and parasitic power loss reduction are presented.

Multi-Angular Flame Measurements and Analysis in a Supersonic Wind Tunnel Using Fiber Based Endoscopes

2015 ◽  
Author(s):  
Lin Ma ◽  
Andrew J. Wickersham ◽  
Wenjiang Xu ◽  
Scott J. Peltier ◽  
Timothy M. Ombrello ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Thermal Management ◽  
High Speed ◽  
Flow Structures ◽  
Data Sets ◽  
Propulsion Systems ◽  
Supersonic Wind Tunnel ◽  
Optical Access ◽  
Equipment Cost ◽  
Pod Analysis

This paper reports new measurements and analysis made in the Research Cell 19 supersonic wind-tunnel facility housed at the Air Force Research Laboratory. The measurements include planar chemiluminescence from multiple angular positions obtained using fiber based endoscopes (FBEs) and the accompanying velocity fields obtained using particle image velocimetry (PIV). The measurements capture the flame dynamics from different angles (e.g., the top and both sides) simultaneously. The analysis of such data by proper orthogonal decomposition (POD) will also be reported. Non-intrusive and full-field imaging measurements provide a wealth of information for model validation and design optimization of propulsion systems. However, it is challenging to obtain such measurements due to various implementation difficulties such as optical access, thermal management, and equipment cost. This work therefore explores the application of FBEs for non-intrusive imaging measurements in supersonic propulsion systems. The FBEs used in this work are demonstrated to overcome many of the practical difficulties and significantly facilitate the measurements. The FBEs are bendable and have relatively small footprints (compared to high-speed cameras), which facilitates line-of-sight optical access. Also, the FBEs can tolerate higher temperatures than high-speed cameras, ameliorating the thermal management issues. Lastly, the FBEs, after customization, can enable the capture of multiple images (e.g., images of the flowfields at multi-angles) onto the same camera chip, greatly reducing the equipment cost of the measurements. The multi-angle data sets, enabled by the FBEs as discussed above, were analyzed by POD to extract the dominating flame modes when examined from various angular positions. Similar analysis was performed on the accompanying PIV data to examine the corresponding modes of the flowfields. The POD analysis provides a quantitative measure of the dominating spatial modes of the flame and flow structures and is an effective mathematical tool to extract key physics from large data sets such as the high-speed measurements collected in this study. However, past POD analysis has been limited to data obtained from one orientation only. The availability of data at multiple angles in this study is expected to provide further insights into the flame and flow structures in high-speed propulsion systems.

Wake and Loss Analysis for a Double Bladed Swept Propeller

2016 ◽  
Author(s):  
Alexandre Capitao Patrao ◽  
Richard Avellán ◽  
Anders Lundbladh ◽  
Tomas Grönstedt
Keyword(s):  
High Speed ◽  
Energy Analysis ◽  
Complex Geometry ◽  
Analysis Method ◽  
Aircraft Wings ◽  
Loss Analysis ◽  
Propeller Wake ◽  
Induced Drag ◽  
Propeller Blades ◽  
Tip Velocity

Inspired by Prandtl’s theory on aircraft wings with minimum induced drag, the authors introduced a double-bladed propeller, the Boxprop, intended for high-speed flight. The basic idea is to join the propeller blades pair-wise at the tip to improve aerodynamics and mechanical properties compared to the conventional propeller. The rather complex geometry of the double blades gives rise to new questions, particularly regarding the aerodynamics. This paper presents a propeller wake energy analysis method which gives a better understanding of the potential performance benefits of the Boxprop and a means to improve its design. CFD analysis of a five bladed Boxprop demonstrated its ability to generate typical levels of cruise thrust at a flight speed of Mach 0.75. The present work shows that the near tip velocity variations in the wake are weaker for this propeller than a conventional one, which is an indication that a counter rotating propeller designed with a Boxprop employed at the front may exhibit lower interaction noise.

scholarly journals Advances in Engine Test Capabilities at the NASA Glenn Research Center’s Propulsion Systems Laboratory

2006 ◽  
Author(s):  
Peter M. Pachlhofer ◽  
Joseph W. Panek ◽  
Dennis J. Dicki ◽  
Barry R. Piendl ◽  
Paul J. Lizanich ◽  
...  
Keyword(s):  
Data Acquisition ◽  
Control Systems ◽  
High Speed ◽  
Video Capture ◽  
Propulsion Systems ◽  
Data Acquisition Systems ◽  
Wide Range ◽  
High Speed Data Acquisition ◽  
High Speed Data ◽  
Simulation Systems

The Propulsion Systems Laboratory at the National Aeronautics and Space Administration (NASA) Glenn Research Center is one of the premier U.S. facilities for research on advanced aeropropulsion systems. The facility can simulate a wide range of altitude and Mach number conditions while supplying the aeropropulsion system with all the support services necessary to operate at those conditions. Test data are recorded on a combination of steady-state and high-speed data-acquisition systems. Recently a number of upgrades were made to the facility to meet demanding new requirements for the latest aeropropulsion concepts and to improve operational efficiency. Improvements were made to data-acquisition systems, facility and engine-control systems, test-condition simulation systems, video capture and display capabilities, and personnel training procedures. This paper discusses the facility’s capabilities, recent upgrades, and planned future improvements.

A SIMULATION APPROACH FOR PLANING BOATS PROPULSION AND MANOEUVRABILITY

2016 ◽  
Vol 158 (B1) ◽  
Author(s):  
A Ircani ◽  
M Martelli ◽  
M Viviani ◽  
M Altosole ◽  
C Podenzana-Bonvino ◽  
...  
Keyword(s):  
High Speed ◽  
High Performance ◽  
Preliminary Design ◽  
Propulsion Systems ◽  
Sea Trial ◽  
Performance Requirements ◽  
High Speed Diesel ◽  
Captive Model Tests ◽  
Speed Up

A comprehensive approach to modelling and simulation of high speed craft dynamics during turning circle and zig-zag manoeuvres is presented in this paper. The high performance requirements for propulsion systems and the increasing attention being paid to planing hull manoeuvring features suggest the need for a thorough investigation into ship dynamics, starting in the preliminary design phase. Dynamic aspects of planing craft during manoeuvres cannot be adequately dealt with by traditional methodologies and purely steady state approaches. For this reason, the boat’s dynamic behaviour is evaluated by means of a time domain simulator, able to represent the hull dynamics, including the mutual interactions with the propulsion system and propulsion controller. Manoeuvrability characteristics are simulated on the basis of captive model tests on planing hulls available in open literature. Compared with previous similar studies, in the present work a possible strategy is introduced to represent roll motion due to the propulsion and steering effects. Finally, the simulation results are compared with sea trial records in order to highlight the capabilities and shortcomings of the proposed method. The case study analysed is a boat equipped with two azimuthal propulsors driven by two high-speed diesel engines that ensure a speed up to 32.5 kn.

Multi-angular Flame Measurements and Analysis in a Supersonic Wind Tunnel Using Fiber-Based Endoscopes

2015 ◽  
Vol 138 (2) ◽  
Author(s):  
Lin Ma ◽  
Andrew J. Wickersham ◽  
Wenjiang Xu ◽  
Scott J. Peltier ◽  
Timothy M. Ombrello ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Thermal Management ◽  
High Speed ◽  
Flow Fields ◽  
Flow Structures ◽  
Data Sets ◽  
Propulsion Systems ◽  
Supersonic Wind Tunnel ◽  
Equipment Cost ◽  
Pod Analysis

This paper reports new measurements and analysis made in the Research Cell 19 supersonic wind-tunnel facility housed at the Air Force Research Laboratory. The measurements include planar chemiluminescence from multiple angular positions obtained using fiber-based endoscopes (FBEs) and the accompanying velocity fields obtained using particle image velocimetry (PIV). The measurements capture the flame dynamics from different angles (e.g., the top and both sides) simultaneously. The analysis of such data by proper orthogonal decomposition (POD) will also be reported. Nonintrusive and full-field imaging measurements provide a wealth of information for model validation and design optimization of propulsion systems. However, it is challenging to obtain such measurements due to various implementation difficulties such as optical access, thermal management, and equipment cost. This work therefore explores the application of the FBEs for nonintrusive imaging measurements in the supersonic propulsion systems. The FBEs used in this work are demonstrated to overcome many of the practical difficulties and significantly facilitate the measurements. The FBEs are bendable and have relatively small footprints (compared to high-speed cameras), which facilitates line-of-sight optical access. Also, the FBEs can tolerate higher temperatures than high-speed cameras, ameliorating the thermal management issues. Finally, the FBEs, after customization, can enable the capture of multiple images (e.g., images of the flow fields at multi-angles) onto the same camera chip, greatly reducing the equipment cost of the measurements. The multi-angle data sets, enabled by the FBEs as discussed above, were analyzed by POD to extract the dominating flame modes when examined from various angular positions. Similar analysis was performed on the accompanying PIV data to examine the corresponding modes of the flow fields. The POD analysis provides a quantitative measure of the dominating spatial modes of the flame and flow structures, and is an effective mathematical tool to extract key physics from large data sets as the high-speed measurements collected in this study. However, the past POD analysis has been limited to data obtained from one orientation only. The availability of data at multiple angles in this study is expected to provide further insights into the flame and flow structures in high-speed propulsion systems.

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