Influence of Contraction Section Shape and Inlet Flow Direction on Supersonic Nozzle Flow and Performance

1972 ◽  
Vol 9 (6) ◽  
pp. 420-427 ◽  
Author(s):  
LLOYD H. BACK ◽  
ROBERT F. CUFFEL ◽  
PAUL F. MASSIER
Keyword(s):  
Flow Direction ◽  
Supersonic Nozzle ◽  
Nozzle Flow ◽  
Inlet Flow ◽  
Section Shape ◽  
And Performance

Design and performance evaluation of a pump-as-turbine micro-hydro test facility with incorporated inlet flow control

2015 ◽  
Vol 78 ◽  
pp. 1-6 ◽  
Author(s):  
D.R. Giosio ◽  
A.D. Henderson ◽  
J.M. Walker ◽  
P.A. Brandner ◽  
J.E. Sargison ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Flow Control ◽  
Test Facility ◽  
Inlet Flow ◽  
And Performance

Numerical Investigation of Film Cooling Effectiveness Including Shockwave Interaction in a Supersonic Nozzle Flow

2022 ◽  
Author(s):  
Manoj Prabakar Sargunaraj ◽  
Andres Torres ◽  
Jose Garduna ◽  
Marcel Otto ◽  
Jayanta S. Kapat ◽  
...  
Keyword(s):  
Numerical Investigation ◽  
Film Cooling ◽  
Supersonic Nozzle ◽  
Nozzle Flow ◽  
Cooling Effectiveness ◽  
Film Cooling Effectiveness

Experiments on water vapour condensation within supersonic nozzle flow generated by an impulse tunnel

2021 ◽  
Vol 134 ◽  
pp. 103473
Author(s):  
Jafar Mahmoudian ◽  
Federico Mazzelli ◽  
Adriano Milazzo ◽  
Ray Malpress ◽  
David R. Buttsworth
Keyword(s):  
Water Vapour ◽  
Supersonic Nozzle ◽  
Nozzle Flow ◽  
Vapour Condensation

scholarly journals Computational and Experimental Study of Supersonic Nozzle Flow and Aft-Deck Interactions

2016 ◽  
Author(s):  
Walter E. Bruce ◽  
Melissa B. Carter ◽  
Alaa A. Elmiligui ◽  
Courtney S. Winski ◽  
Sudheer Nayani ◽  
...  
Keyword(s):  
Experimental Study ◽  
Supersonic Nozzle ◽  
Nozzle Flow

scholarly journals Numerical Simulation of Reactive Flows in Overexpanded Supersonic Nozzle with Film Cooling

2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
Mohamed Sellam ◽  
Amer Chpoun
Keyword(s):  
Film Cooling ◽  
Structural Integrity ◽  
Safety Issue ◽  
Rocket Engine ◽  
Supersonic Nozzle ◽  
Nozzle Geometry ◽  
Nozzle Flow ◽  
Rocket Engines ◽  
Flow Conditions ◽  
Reactive Flows

Reignition phenomena occurring in a supersonic nozzle flow may present a crucial safety issue for rocket propulsion systems. These phenomena concern mainly rocket engines which use H2gas (GH2) in the film cooling device, particularly when the nozzle operates under over expanded flow conditions at sea level or at low altitudes. Consequently, the induced wall thermal loads can lead to the nozzle geometry alteration, which in turn, leads to the appearance of strong side loads that may be detrimental to the rocket engine structural integrity. It is therefore necessary to understand both aerodynamic and chemical mechanisms that are at the origin of these processes. This paper is a numerical contribution which reports results from CFD analysis carried out for supersonic reactive flows in a planar nozzle cooled with GH2film. Like the experimental observations, CFD simulations showed their ability to highlight these phenomena for the same nozzle flow conditions. Induced thermal load are also analyzed in terms of cooling efficiency and the results already give an idea on their magnitude. It was also shown that slightly increasing the film injection pressure can avoid the reignition phenomena by moving the separation shock towards the nozzle exit section.

Impact of the Expansion Ratio on the Unsteady Aerodynamics and Performance of a HP Axial Turbine

2016 ◽  
Author(s):  
P. Gaetani ◽  
G. Persico ◽  
A. Spinelli ◽  
A. Mora
Keyword(s):  
Flow Field ◽  
Incidence Angle ◽  
Flow Direction ◽  
Axial Flow ◽  
Unsteady Aerodynamics ◽  
Fast Response ◽  
Expansion Ratio ◽  
Operating Conditions ◽  
Inlet Temperature ◽  
And Performance

In the frame of the European research project RECORD, the flow field within a HP axial-flow turbine model was investigated experimentally for several operating conditions. A number of studies on stator-rotor interaction in HP turbines for subsonic as well as transonic/supersonic conditions were proposed in the last decades, but none of them compared different conditions for the same geometry. In this paper, the transonic condition is investigated and compared to three subsonic ones, in the frame of an entirely new experimental campaign. The research was performed at the Laboratorio di Fluidodinamica delle Macchine of the Politecnico di Milano (Italy), where a cold-flow, closed-loop test rig is available for detailed studies on turbines and compressors. The boundary conditions resulted in keeping constant both the turbine inlet temperature and the stage outlet absolute flow direction; so far, while the expansion ratio was varied, the rotational speed was also modified accordingly. The analysis was performed by means of a conventional five hole probe in the stator – rotor axial gap and by a fast response aerodynamic probe downstream of the rotor. The local time-averaged and phase-resolved flow field was then derived and used to analyze the stage aerodynamics and performance. Results show that the stage expansion ratio has a dramatic impact on both the rotor aerodynamics and stage performance. In particular, Mach number effects are recognized in the stator cascade that passes from transonic to low subsonic conditions. On the rotor cascade the reduction of expansion ratio reduces significantly the Mach and Reynolds numbers and increases the incidence angle as well; the rotor loss mechanics as well as the vane-rotor interaction are greatly amplified. Correspondingly a significant variation of stage overall efficiency is recorded.

Development of a Freejet Capability for Evaluating Inlet-Engine Compatibility

1991 ◽  
Author(s):  
P. V. Maywald ◽  
D. K. Beale
Keyword(s):  
Technology Development ◽  
Support Systems ◽  
Supersonic Nozzle ◽  
Test Facility ◽  
Nozzle Flow ◽  
Propulsion Systems ◽  
Turbine Engine ◽  
Development Center ◽  
Subsonic Nozzle

The Arnold Engineering Development Center (AEDC) is installing a freejet test capability into the Aero-propulsion Systems Test Facility (ASTF). The freejet will provide the capability for ground determination of turbine engine and aircraft inlet compatibility by utilizing full-scale inlets and engines as test articles in a simulated flight environment. The details of the design, installation, and projected testing capability are described for a 57 ft2 supersonic nozzle and a 77 ft2 subsonic nozzle. Support systems for mechanically pitching and yawing the freejet nozzles are also reported as well as the test cell hardware for capturing the freejet nozzle flow. The plans for demonstrating the freejet capability prior to its initial operational date are explained. The technology development efforts to validate and utilize the freejet test capabilities are also described.

Military Engine Response to Compressor Inlet Stratified Pressure Distortion by an Integrated CFD Analysis

2006 ◽  
Author(s):  
Leonardo Melloni ◽  
Petros Kotsiopoulos ◽  
Anthony Jackson ◽  
Vassilios Pachidis ◽  
Pericles Pilidis
Keyword(s):  
Engine Performance ◽  
Low Pressure ◽  
Operating Conditions ◽  
High Fidelity ◽  
Inlet Flow ◽  
Performance Simulation ◽  
Simulation Strategy ◽  
Compressor Inlet ◽  
And Performance ◽  
Pressure Compressor

Especially in aircraft applications, the inlet flow is quite often non uniform resulting in severe changes in compressor performance and hence, engine performance. The magnitude of this phenomenon can be amplified in military engines due to the complex shape of intake ducts and the extreme flight conditions. The usual approach to engine performance simulation is based on non-dimensional maps for compressors and turbines and assumes uniform flow characteristics throughout the engine. In the context of the whole engine performance, component-level, complex physical processes, such as compressor inlet flow distortion, can not be captured and analyzed. This work adopts a simulation strategy that allows the performance characteristics of an engine component, resolved from a detailed, high-fidelity analysis, to be transferred to an engine system analysis carried out at a lower level of fidelity. The methodology described in this paper utilizes an object-oriented, zero-dimensional gas turbine modeling and performance simulation system and a high-fidelity, three-dimensional, computational fluid dynamics (CFD), low-pressure compressor model. The CFD model is based on the overall geometry and performance of the low-pressure compressor of a modern, two-spool, low by-pass ratio (LBR) military turbofan engine and is subjected to both clean and distorted inlet flows. The analysis involves the generation of two characteristic maps for the first stage of the LP compressor from CFD simulations that account for a range of operating conditions and power settings with a uniform and a distorted inlet flow. The same simulation strategy could be adopted for other engine components such as the intake or the high-pressure compressor and for different magnitudes and types of distortion (i.e. radial, circumferential). By integrating the CFD-generated maps, into the 0-D engine analysis system, this paper presents a relative comparison between the ‘uniform-inlet’ engine performance (baseline compressor stage map) and the engine performance obtained after using the map accounting for a typical extent of stratified inlet distortion. The analysis carried out by this study, demonstrates relative changes in the simulated engine performance larger than 1%.

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