scholarly journals Schlieren Imaging of Single-Fin Missile models in a De-Laval Nozzle Test Section

2021 ◽  
Vol 13 (2) ◽  
pp. 151-162
Author(s):  
Nayhel SHARMA ◽  
Bharat Ankur DOGRA ◽  
Rakesh KUMAR
Keyword(s):  
Experimental Study ◽  
Fluid Flow ◽  
Test Section ◽  
Laval Nozzle ◽  
Flow Behavior ◽  
Flow Conditions ◽  
Schlieren Imaging ◽  
Schlieren Technique ◽  
De Laval Nozzle ◽  
Schlieren Photography

The experimental study (Schlieren photography) to characterize the flow behavior around a semi-cylindrical missile model having a single planar and wrap-around fin surface is performed inside a modified De-Laval nozzle test section capable of sustaining an airflow at Mach number ~1.7M. The images obtained from this schlieren technique is compared with flow field contour images of the similar missile models at similar flow conditions. The experiments are performed on a modified two-walled glassed section to assist the Schlieren imaging. The test section is calibrated preliminary to the experiments to assure the supersonic fluid flow. A comparison of flow images around the two types of fins further helps in characterizing the flow in their vicinity.

Experimental Study of Confined Turbulent Vortical Flow in a Narrow Annulus

2014 ◽  
Author(s):  
Yuri Perelstein ◽  
Matthieu Gancedo ◽  
Charles Farbos de Luzan ◽  
Ephraim Gutmark ◽  
Thomas Frosell
Keyword(s):  
Experimental Study ◽  
Flow Field ◽  
Test Section ◽  
Flow Behavior ◽  
Laser Sheet ◽  
Calibration Method ◽  
Stereoscopic Particle Image Velocimetry ◽  
Vortical Flow ◽  
Shear Stresses ◽  
Outer Annulus

An experimental study was carried out to investigate the turbulent flow field of confined vortical flow in a narrow annulus. The test section consists of two concentric annuli that are separated by a tube with four equally spaced rectangular apertures. Water is passing from the inner annulus to the outer annulus and the main region of interest is near aforementioned rectangular holes. Flow velocity was measured using a stereoscopic particle image velocimetry (PIV) system. The small size of the outer annulus required development of multiple improvements to the PIV system. Stereoscopic calibration within the curved and narrow annulus required development of a calibration method that ensured accurate alignment of the laser sheet to provide an accurate polynomial mapping of the physical coordinates to the pixel location on the ICCD chips of the cameras. Macro lenses were used to provide the desired field of view. Test section dimensions required accurate vertical repositioning of the cameras and the laser within the measurement plane. This was implemented using a two-axis positioning system. Reflections within the outer annulus required development of a polyurethane based paint that reflected the laser light with a shifted wavelength. The paint survived high shear stresses and pressure gradients during testing. Three dimensional flow field was assembled based on measurements taken, providing insight into the behavior of the flow as it exits the aperture and mixes in the outer annulus. A vortex core was identified. The results of measurements are compared to CFD results and serve as a tool validating the CFD model. Both the CFD and the measured results predict similar trends in flow behavior, showing strong radial and tangential components of velocity at the plane coincident with the edge of the hole.

Development of Test Rigs to Investigate Fluid Flow and Heat Transfer in a Stirling Engine Heater Head

2018 ◽  
Author(s):  
Pawan Kumar Yadav ◽  
Songgang Qiu ◽  
Koji Yanaga
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Test Section ◽  
Stirling Engine ◽  
Oscillating Flow ◽  
Flow Conditions ◽  
Test Rig ◽  
Charged Fluid ◽  
Preliminary Results ◽  
Flow And Heat Transfer

To study the fluid flow and heat transfer in a Stirling Engine Heater Head (HH), two benchtop test rigs were designed and manufactured. One is to evaluate flow loss in oscillating flow conditions and another is to evaluate heat transfer in unidirectional flow conditions. The main test section-heater head, is additively manufactured; the test section also consists of an additively manufactured regenerator and a heat rejecter. For fluid flow test rig, a linear actuator from Parker generates and maintains the oscillating flow by driving a piston in sinusoidal motion. The piston is sealed against the charged fluid using Trelleborg seals. At room temperature, by varying the charge pressure, frequency, and stroke length, multiple test conditions can be achieved. For heat transfer test rig, a Gast’s high-flow, low-pressure compressed air blower is used to deliver the flow. The data acquisition (DAQ) is comprised of National Instruments’ cDAQ and modules to measure the piston’s motion in real time, pressure with Kistler’s pressure transducers, and the temperatures with OMEGA’s thermocouples, located at both the inlet and outlet of the heater head. Presented also are the testing procedures, some expected results, and the Sage outputs that will be used to check against the measured data from the test rigs, including some preliminary results. Based on the preliminary results, pressure and position curves were sinusoidal, which is expected of oscillating motions, meaning the test rig is operating well.

An Experimental Study on the Transport of Sediment in Sewer Pipes with a Permanent Deposit

1992 ◽  
Vol 25 (8) ◽  
pp. 115-122 ◽  
Author(s):  
G. S. Perrusquía
Keyword(s):  
Experimental Study ◽  
Critical Shear Stress ◽  
Side Wall ◽  
Bedload Transport ◽  
Flow Conditions ◽  
Sewer Pipes ◽  
Sediment Bed ◽  
Concrete Pipe ◽  
Geometric Factors ◽  
Particle Parameters

An experimental study of the transport of sediment in a part-full pipe was carried out in a concrete pipe. The experiments were confined to bedload transport. The purpose of this study was to analyze the flow conditions that characterize the stream traction in pipe channels and their relationship to flow resistance and sediment transport rate. Three procedures used in this kind of experimental study were tested and found valid: 1) the vertical velocity distribution near the sediment bed can be described by the velocity-defect law, 2) the side wall elimination procedure can be used to compute the hydraulic radius of the sediment bed, and 3) the critical shear stress of the sediment particles can be obtained by using Shields' diagram. A relationship to estimate bedload transport, based on dimensional analysis, was proposed. This was expressed in terms of both flow and particle parameters as well as geometric factors. Further experimental work is recommended before this relationship can be fully incorporated in a simulation model for the analysis of storm sewers.

An improved de Laval nozzle experiment

2021 ◽  
pp. 030641902110341
Author(s):  
Nicholas Goodman ◽  
Brian J Leege ◽  
Peter E Johnson
Keyword(s):  
Data Acquisition ◽  
Laval Nozzle ◽  
Flow Characteristics ◽  
Data Acquisition System ◽  
Isentropic Flow ◽  
Hands On ◽  
De Laval Nozzle ◽  
Physical Phenomena ◽  
The Impact ◽  
The Relationship

Exposing students to hands-on experiments has been a common approach to illustrating complex physical phenomena that have been otherwise modelled solely mathematically. Compressible, isentropic flow in a duct is an example of such a phenomenon, and it is often demonstrated via a de Laval nozzle experiment. We have improved an existing converging/diverging nozzle experiment so that students can modify the location of the normal shock that develops in the diverging portion to better understand the relationship between the shock and the pressure. We have also improved the data acquisition system for this experiment and explained how visualisation of the standing shock is now possible. The results of the updated system demonstrate that the accuracy of the isentropic flow characteristics has not been lost. Through pre- and post-laboratory quizzes, we show the impact on student learning as well.

Fluid Flow Field in the Annulus of Boiling Water (BWR) Nuclear Reactors Under Normal and Accident Conditions

2009 ◽  
Author(s):  
Raju Ananth ◽  
Karen Fujikawa ◽  
Jay Gillis
Keyword(s):  
Fluid Flow ◽  
Velocity Field ◽  
Flow Field ◽  
Pressure Vessel ◽  
Theoretical Study ◽  
Nuclear Reactors ◽  
Boiling Water ◽  
Flow Conditions ◽  
Accident Conditions ◽  
Reactor Pressure

This paper presents a theoretical study of the velocity field in the annulus formed between the Reactor Pressure Vessel (RPV) and the shroud of a Boiling Water Reactor (BWR) under normal and accident flow conditions. Simplified geometry and an ideal irrotational flow are assumed to solve the problem using velocity potentials.

Effects of Nano-Nozzles Cross-Sectional Geometry on Fluid Flow: Molecular Dynamic Simulation

2017 ◽  
Vol 34 (5) ◽  
pp. 667-678 ◽  
Author(s):  
H. Nowruzi ◽  
H. Ghassemi
Keyword(s):  
Fluid Flow ◽  
Velocity Profile ◽  
Cross Sections ◽  
Md Simulation ◽  
Flow Behavior ◽  
Water Model ◽  
Physical Parameters ◽  
Cross Sectional ◽  
Behavior Characteristics ◽  
Fanning Friction Factor

AbstractNano-nozzles are an essential part of the nano electromechanical systems (NEMS). Cross-sectional geometry of nano-nozzles has a significant role on the fluid flow inside them. So, main purpose of the present study is related to the effects of different symmetrical cross-sections on the fluid flow behavior inside of nano-nozzles. To this accomplishment, five different cross-sectional geometries (equilateral triangle, square, regular hexagon, elliptical and circular) are investigated by using molecular dynamics (MD) simulation. In addition, TIP4P is used for atomistic water model. In order to evaluate the fluid flow behavior, non-dimensional physical parameters such as Fanning friction factor, velocity profile and density number are analyzed. Obtained results are shown that the flow behavior characteristics appreciably depend on the geometry of nano-nozzle's cross-section. Velocity profile and density number for five different cross sections of nano-nozzle at three various measurement gauges are presented and discussed.

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