Experimental Investigation of Methods for Improving the Dynamic Response of a Twin-Spool Turbojet Engine

1971 ◽  
Vol 93 (4) ◽  
pp. 418-424 ◽  
Author(s):  
A. J. Fawke ◽  
H. I. H. Saravanamuttoo
Keyword(s):  
Experimental Investigation ◽  
Dynamic Response ◽  
Excellent Agreement ◽  
Digital Computer ◽  
Experimental Tests ◽  
Turbojet Engine ◽  
Surge Margin

This paper describes experimental tests carried out on a twin-spool turbojet to confirm earlier simulator predictions of methods of improving the dynamic response. The engine was controlled by a digital computer, permitting ready changes of control schedules. It was verified that dynamic response could be improved by trading HP surge margin for LP surge margin by suitable variation of the nozzle area. Operating trajectories were obtained on both compressor characteristics during both accelerations and decelerations and excellent agreement with simulator results was obtained.

Experimental Investigation of Flowrate Irregularity in Rotary Gear Pumps

1992 ◽  
Author(s):  
G. Mimmi
Keyword(s):  
Experimental Investigation ◽  
Flow Rate ◽  
Experimental Tests ◽  
Periodic Variation ◽  
Experimental Results ◽  
Gear Pump ◽  
Gear Pumps ◽  
Hot Film ◽  
Instantaneous Flow Rate ◽  
External Gear Pump

Abstract In a previous paper the author proposed a method to reduce the periodic variation in flow rate for an external gear pump. To verify the experimental results, a series of experimental tests on a expressly realized gear pump, was carried out. The pump was equipped with relieving grooves milled into the side plates. The tests were done on a closed piping specifically realized and equipped for measuring the instantaneous flow rate of the fluid through a wedge-shaped hot film probe.

In-plane bending of a large 90° smooth bend

1966 ◽  
Vol 1 (4) ◽  
pp. 290-300 ◽  
Author(s):  
G E Findlay ◽  
J Spence
Keyword(s):  
Experimental Investigation ◽  
Asymptotic Solution ◽  
Nuclear Power Station ◽  
Excellent Agreement ◽  
Nuclear Power ◽  
Reactor Vessel ◽  
Power Station ◽  
Plane Bending ◽  
Extensive Computation

An experimental investigation has been conducted on a 6 ft 6 in diameter 90° smooth bend which forms part of the outlet ducting of Number 2 reactor vessel at Sizewell nuclear power station. The results of the investigation show excellent agreement with various available theories, both for stresses and flexibility factors. The theories themselves are discussed and it is concluded that the asymptotic solution of Clark and Reissner, largely neglected in this country, has distinct advantages in many cases, being relatively simple to use and giving comparable results with other theories which require extensive computation.

Design and Testing of a Miniaturized Five-Hole Fast Response Pressure Probe With Large Frequency Bandwidth and High Angular Sensitivity

2019 ◽  
Vol 141 (10) ◽  
Author(s):  
Elissavet Boufidi ◽  
Marco Alati ◽  
Fabrizio Fontaneto ◽  
Sergio Lavagnoli
Keyword(s):  
Dynamic Response ◽  
Three Dimensional ◽  
Experimental Tests ◽  
Fast Response ◽  
Pressure Probe ◽  
Probe Design ◽  
Directional Sensitivity ◽  
Angular Sensitivity ◽  
Numerical Predictions ◽  
Response Pressure

Abstract A miniaturized five-hole fast response pressure probe is presented, and the methods for the aerodynamic design and performance characterization are explained in detail. The probe design is aimed for three-dimensional (3D) time-resolved measurements in turbomachinery flows, therefore requiring high frequency response and directional sensitivity. It features five encapsulated piezoresistive pressure transducers, recessed inside the probe hemispherical head. Theoretical and numerical analyses are carried out to estimate the dynamic response of the pressure tap line-cavity systems and to investigate unsteady effects that can influence the pressure readings. A prototype is manufactured and submitted to experimental tests that demonstrate performance in line with the theoretical and numerical predictions of the dynamic response: the natural frequency of the central and lateral taps extends to 200 and 25 kHz, respectively. An aerodynamic calibration is also performed at different Reynolds and Mach numbers. The probe geometry offers a good angular sensitivity in a ± 30 deg incidence range, while a frequency analysis reveals the presence of pressure oscillations related to vortex shedding at large angles of attack.

Experimental Investigation of Spacecraft In-Flight Disturbances and Dynamic Response

1997 ◽  
Vol 34 (2) ◽  
pp. 199-204 ◽  
Author(s):  
Stanley E. Woodard ◽  
Richard R. Lay ◽  
Robert F. Jarnot ◽  
David A. Gell
Keyword(s):  
Experimental Investigation ◽  
Dynamic Response

Analysis of composite stiffener under successive impact and bending test

2017 ◽  
Vol 36 (17) ◽  
pp. 1225-1238 ◽  
Author(s):  
Muhammad Ridha ◽  
Tong-Earn Tay ◽  
Sven Werner ◽  
Paul Joern ◽  
Vincent Beng Chye Tan
Keyword(s):  
Experimental Investigation ◽  
Impact Strength ◽  
Bending Strength ◽  
Impact Damage ◽  
Experimental Tests ◽  
Bending Test ◽  
Successful Prediction ◽  
Bend Tests ◽  
Point Bend ◽  
Extent Of Damage

In this article, we present the analysis, modelling and experimental investigation of composite omega stiffeners from non-penetrating impact to bending-after-impact. We used advanced computational methods to determine the extent of damage due to impact and, without many simplifications to the damage, predict the residual bending-after-impact strength under four-point-bend tests. The predicted sizes and patterns of impact damage, and the subsequent predicted bending strengths are compared to experimental tests of omega stiffeners. This work shows that preserving the details and fidelity of damage in the computational model is critical to successful prediction of residual strength. It was also found that modifying the design of the stiffeners by changing the orientation of some of the plies reduces the extent of impact damage and increases residual bending strength.

An Experimental Investigation of Airfoil Performance in Wet Gas Flow

2008 ◽  
Author(s):  
Trond G. Gru¨ner ◽  
Lars E. Bakken ◽  
Lars Brenne ◽  
Tor Bjo̸rge
Keyword(s):  
Experimental Investigation ◽  
Gas Flow ◽  
Boundary Layer Separation ◽  
Qualitative Description ◽  
Water Mixture ◽  
Surge Margin ◽  
Wet Gas ◽  
Flow Mechanisms ◽  
Wet Condition ◽  
Liquid Mass Flow Rate

Development of wet gas compressors is challenging due to the liquid phase impact on performance. Experimental investigation of airfoil behavior in wet condition contributes to a revised compressor design and increased understanding of multiphase flow mechanisms. The performance of an airfoil was investigated in wet gas flow. An air-water mixture was used as the experimental fluid. The influence of wet gas flow on airfoil performance was investigated at different angles of incidence and gas volume fractions. A qualitative description of the complex physical process observed when liquid is introduced into the flow field is given. Airfoil performance was degraded at increased liquid mass flow rate owing to premature boundary layer separation. The initiation of separation was observed as a local film thickening, followed by increased liquid film fluctuations. A continuity wave was observed surrounding the airfoil, forming a U shape of increased liquid concentration. The wave was initiated by deposited droplets and the formation of secondary droplets. The investigation reveals that compressor operating range, surge and stall margins are affected by the wet gas fluid. Reviewed literature and experiments confirm a reduced stall and surge margin when a compressor is exposed to wet gas. Further investigation will involve sub-scale impeller tests to determine the effects on the performance and stability ranges.

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