scholarly journals Simulation Based Prediction of Compliance Induced Shape Deviations in Internal Traverse Grinding

2021 ◽  
Vol 5 (2) ◽  
pp. 60
Author(s):  
Tountzer Tsagkir Dereli ◽  
Nils Schmidt ◽  
Tim Furlan ◽  
Raphael Holtermann ◽  
Dirk Biermann ◽  
...  
Keyword(s):  
High Speed ◽  
Force Measurement ◽  
Axial Direction ◽  
Experimental Investigations ◽  
Measurement Technology ◽  
Shape Accuracy ◽  
Shape Deviations ◽  
Process Forces ◽  
Internal Traverse Grinding ◽  
Traverse Grinding

Internal traverse grinding (ITG) using electroplated cBN tools in high-speed grinding conditions is a highly efficient manufacturing process for bore machining in a single axial stroke. However, process control is difficult. Due to the axial direction of feed, changes in process normal force and thus radial deflection of the tool and workpiece spindle system, lead to deviations in the workpiece contour along the length of the bore, especially at tool exit. Simulations including this effect could provide a tool to design processes which enhance shape accuracy of components. A geometrical physically-based simulation is herein developed to model the influence of system compliance on the resulting workpiece contour. Realistic tool topographies, obtained from measurements, are combined with an FE-calibrated surrogate model for process forces and with an empirical compliance model. In quasistatic experimental investigations, the spindle deflection is determined in relation to the acting normal forces by using piezoelectric force measuring elements and eddy current sensors. In grinding tests with in-process force measurement technology and followed by measurement of the resulting workpiece contours, the simulation system is validated. The process forces and the resulting characteristic shape deviations are predicted in good qualitative accordance with the experimental results.

scholarly journals Numerical and Experimental Investigations on Vocal Fold Approximation in Healthy and Simulated Unilateral Vocal Fold Paralysis

2021 ◽  
Vol 11 (4) ◽  
pp. 1817
Author(s):  
Zheng Li ◽  
Azure Wilson ◽  
Lea Sayce ◽  
Amit Avhad ◽  
Bernard Rousseau ◽  
...  
Keyword(s):  
Computational Model ◽  
Vocal Fold ◽  
High Speed ◽  
Computational Models ◽  
Ex Vivo ◽  
Vocal Fold Paralysis ◽  
Future Application ◽  
Experimental Investigations ◽  
Type I ◽  
Mri Scans

We have developed a novel surgical/computational model for the investigation of unilat-eral vocal fold paralysis (UVFP) which will be used to inform future in silico approaches to improve surgical outcomes in type I thyroplasty. Healthy phonation (HP) was achieved using cricothyroid suture approximation on both sides of the larynx to generate symmetrical vocal fold closure. Following high-speed videoendoscopy (HSV) capture, sutures on the right side of the larynx were removed, partially releasing tension unilaterally and generating asymmetric vocal fold closure characteristic of UVFP (sUVFP condition). HSV revealed symmetric vibration in HP, while in sUVFP the sutured side demonstrated a higher frequency (10–11%). For the computational model, ex vivo magnetic resonance imaging (MRI) scans were captured at three configurations: non-approximated (NA), HP, and sUVFP. A finite-element method (FEM) model was built, in which cartilage displacements from the MRI images were used to prescribe the adduction, and the vocal fold deformation was simulated before the eigenmode calculation. The results showed that the frequency comparison between the two sides was consistent with observations from HSV. This alignment between the surgical and computational models supports the future application of these methods for the investigation of treatment for UVFP.

scholarly journals Shock Tube as an Impulsive Application Device

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Soumya Ranjan Nanda ◽  
Sumit Agarwal ◽  
Vinayak Kulkarni ◽  
Niranjan Sahoo
Keyword(s):  
Heat Transfer ◽  
Shock Tube ◽  
High Speed ◽  
Force Measurement ◽  
Peak Load ◽  
Wave Force ◽  
Impulsive Loading ◽  
Force Balance ◽  
Test Model ◽  
Impulse Facility

Current investigations solely focus on application of an impulse facility in diverse area of high-speed aerodynamics and structural mechanics. Shock tube, the fundamental impulse facility, is specially designed and calibrated for present objectives. Force measurement experiments are performed on a hemispherical test model integrated with the stress wave force balance. Similar test model is considered for heat transfer measurements using coaxial thermocouple. Force and heat transfer experiments demonstrated that the strain gauge and thermocouple have lag time of 11.5 and 9 microseconds, respectively. Response time of these sensors in measuring the peak load is also measured successfully using shock tube facility. As an outcome, these sensors are found to be suitable for impulse testing. Lastly, the response of aluminum plates subjected to impulsive loading is analyzed by measuring the in-plane strain produced during deformation. Thus, possibility of forming tests in shock is also confirmed.

Experimental Inverstigations On the Pressure Fluctuations in the Sealing Gap of Dry Gas Seals with Embedded Pressure Sensors

2021 ◽  
Author(s):  
Jingjing Luo ◽  
Dieter Brillert
Keyword(s):  
High Speed ◽  
Gas Flow ◽  
Static Pressure ◽  
Pressure Sensors ◽  
Operating Conditions ◽  
Test Facility ◽  
Experimental Investigations ◽  
Mechanical Seals ◽  
Process Gas ◽  
Sealing Gap

Abstract Dry gas lubricated non-contacting mechanical seals (DGS), most commonly found in centrifugal compressors, prevent the process gas flow into the atmosphere. Especially when high speed is combined with high pressure, DGS is the preferred choice over other sealing alternatives. In order to investigate the flow field in the sealing gap and to facilitate the numerical prediction of the seal performance, a dedicated test facility is developed to carry out the measurement of key parameters in the gas film. Gas in the sealing film varies according to the seal inlet pressure, and the thickness of gas film depends on this fluctuated pressure. In this paper, the test facility, measurement methods and the first results of static pressure measurements in the sealing gap of the DGS obtained in the described test facility are presented. An industry DGS with three-dimensional grooves on the surface of the rotating ring, where experimental investigations take place, is used. The static pressure in the gas film is measured, up to 20 bar and 8,100 rpm, by several high frequency ultraminiature pressure transducers embedded into the stationary ring. The experimental results are discussed and compared with the numerical model programmed in MATLAB, the characteristic and magnitude of which have a good agreement with the numerical simulations. It suggests the feasibility of measuring pressure profiles of the standard industry DGS under pressurized dynamic operating conditions without altering the key components of the seal and thereby affecting the seal performance.

Turbine Nozzle Endwall Phantom Cooling With Compound Angled Pressure Side Injection

2018 ◽  
Author(s):  
Kevin Liu ◽  
Hongzhou Xu ◽  
Michael Fox
Keyword(s):  
Film Cooling ◽  
High Speed ◽  
Axial Direction ◽  
Secondary Flows ◽  
Test Case ◽  
Pressure Side ◽  
Complex Flow ◽  
Trailing Edge ◽  
Cooling Effectiveness ◽  
Extended Area

Cooling of the turbine nozzle endwall is challenging due to its complex flow field involving strong secondary flows. Increasingly-effective cooling schemes are required to meet the higher turbine inlet temperatures required by today’s gas turbine applications. Therefore, in order to cool the endwall surface near the pressure side of the airfoil and the trailing edge extended area, the spent cooling air from the airfoil film cooling and pressure side discharge slots, referred to as “phantom cooling” is utilized. This paper studies the effect of compound angled pressure side injection on nozzle endwall surface. The measurements were conducted in a high speed linear cascade, which consists of three nozzle vanes and four flow passages. Two nozzle test models with a similar film cooling design were investigated, one with an axial pressure side film cooling row and trailing edge slots; the other with the same cooling features but with compound angled injection, aiming at the test endwall. Phantom cooling effectiveness on the endwall was measured using a Pressure Sensitive Paint (PSP) technique through the mass transfer analogy. Two-dimensional phantom cooling effectiveness distributions on the endwall surface are presented for four MFR (Mass Flow Ratio) values in each test case. Then the phantom cooling effectiveness distributions are pitchwise-averaged along the axial direction and comparisons were made to show the effect of the compound angled injection. The results indicated that the endwall phantom cooling effectiveness increases with the MFR significantly. A compound angle of the pressure side slots also enhanced the endwall phantom cooling significantly. For combined injections, the phantom cooling effectiveness is much higher than the pressure side slots injection only in the endwall downstream extended area.

Prototype Design of a High-Speed Viscous Air Spindle

2008 ◽  
Author(s):  
Guido M. J. Delhaes ◽  
Anton van Beek ◽  
Ron A. J. van Ostayen ◽  
Robert H. Munnig Schmidt
Keyword(s):  
High Speed ◽  
Load Capacity ◽  
Axial Direction ◽  
Cylindrical Part ◽  
Traction Forces ◽  
Micro Cutting ◽  
Tool Holder ◽  
Air Spindle ◽  
Prototype Design

In this paper an innovative air driven spindle for micro cutting applications is presented. The spindle uses a viscous traction concept which has the advantage that the viscous traction forces can act directly on the cylindrical part of the tool, which makes the tool-holder redundant. Furthermore, the tool can be actuated in the axial direction within the housing. In this paper the concept of the viscous turbine, a design of a prototype spindle along with the traction and load-capacity of the spindle are discussed.

Flow-Induced Vibration of a Large-Diameter Elbow Piping Based on Random Force Measurement Caused by Conveying Fluid: Visualization Test Results

2005 ◽  
Author(s):  
Tomomichi Nakamura ◽  
Tadashi Shiraishi ◽  
Yoshihide Ishitani ◽  
Hisato Watakabe ◽  
Hiromi Sago ◽  
...  
Keyword(s):  
Force Measurement ◽  
Large Diameter ◽  
Pressure Fluctuations ◽  
Pressure Sensors ◽  
Maximum Flow ◽  
Axial Direction ◽  
Random Force ◽  
Test Facility ◽  
Flow Induced Vibration ◽  
Correlation Lengths

A 1/3 scale flow-induced vibration test facility that simulates the hot-leg piping of the JNC sodium-cooled fast reactor (JSFR) is used to investigate the pressure fluctuations of the pipe, where the high velocity fluid flows inside the piping. By the measurement of the pressure drop in the elbow piping while changing the Reynolds number, the similarity law of this model is confirmed. To evaluate the flow-induced vibrations for the hot-leg and cold-leg pipes, the random force distributions along the pipe and their correlations are measured with pressure sensors in a water loop. It is found that a flow velocity-dependent periodic phenomenon in the rear region of the elbow, and the maximum flow-induced random vibration force in the pipe are observed in the region of flow separation downstream the elbow. Finally, a design method is proposed with power spectral densities of the pressure fluctuations classified into four sections, correlation lengths in the axial direction divided into three sections, and with correlation lengths in the tangential direction into four sections.

scholarly journals Prechamber optimal selection for a two stage turbulent jet ignition type combustion system in CNG-fuelled engine

2019 ◽  
Vol 176 (1) ◽  
pp. 16-26 ◽  
Author(s):  
Ireneusz PIELECHA ◽  
Wojciech BUESCHKE ◽  
Maciej SKOWRON ◽  
Łukasz FIEDKIEWICZ ◽  
Filip SZWAJCA ◽  
...  
Keyword(s):  
High Speed ◽  
Internal Combustion Engines ◽  
Combustion Process ◽  
Optimization Methods ◽  
Turbulent Jet ◽  
Experimental Investigations ◽  
Combustion System ◽  
Two Stage ◽  
Lean Burn ◽  
High Speed Engine

Searching for further reduction of fuel consumption simultaneously with the reduction of toxic compounds emission new systems for lean-mixture combustion for SI engines are being discussed by many manufacturers. Within the European GasOn-Project (Gas Only Internal Combustion Engines) the two-stage combustion and Turbulent Jet Ignition concept for CNG-fuelled high speed engine has been proposed and thoroughly investigated where the reduction of gas consumption and increasing of engine efficiency together with the reduction of emission, especially CO2 was expected. In the investigated cases the lean-burn combustion process was conducted with selection of the most effective pre-combustion chamber. The experimental investigations have been performed on single-cylinder AVL5804 research engine, which has been modified to SI and CNG fuelling. For the analysis of the thermodynamic, operational and emission indexes very advanced equipment has been applied. Based on the measuring results achieved for different pre-chamber config-urations the extended methodology of polioptimization by pre-chamber selection and the shape of main chamber in the piston crown for proposed combustion system has been described and discussed. The results of the three versions of the optimization methods have been comparatively summarized in conclusions.

scholarly journals MEASURING DISPLACEMENT AND VELOCITY OF A STRIKER USING A RADIO-INTERFEROMETER

2019 ◽  
Vol 81 (1) ◽  
pp. 118-128
Author(s):  
V. V. Balandin ◽  
V. V. Balandin ◽  
V. V. Parkhachev
Keyword(s):  
High Speed ◽  
Radio Interferometer ◽  
Experimental Investigations ◽  
X Ray ◽  
Gas Gun ◽  
Impact Interaction ◽  
Ballistic Experiment ◽  
Wide Range ◽  
Series Of Experiments ◽  
Error Of Measurement

Investigating impact interaction of solid and deformed bodies with obstacles of various physical natures requires developing experimental methodologies of registering the parameters of the interaction process. In experimental investigations of impact interaction of solids, it is common practice to measure displacement of strikers as a function of time, as well as their velocity and deceleration. To determine the displacement and velocity of a striker, a radio-interferometric methodology of registering the displacement of its rear end is proposed. In contrast with the registration methods based on high-speed filming and pulsed X-ray photography, the method using a millimeter-range radio-interferometer provides continuous high-accuracy registering of the displacement of the rear end of a striker in a wide range of displacement values. To test the effectiveness of the methodology, a series of experiments have been conducted on registering the motion of a cylindrical striker of an aluminum alloy, fired from a 20mm-dia gas gun. The displacement of the striker was also monitored using high-speed filming. The results of measuring using the two methodologies differ within the limits of the error of measurement. Based on the results of the above experiments, it has been concluded that the methodology of determining the displacement and velocity of strikers in a ballistic experiment using a mm-range radio-interferometer makes it possible to measure practically continuously large displacements (100 mm and larger) to a safe accuracy. The present methodology can be used for measuring the displacement and velocity of the rear end of a striker interacting with obstacles of various physical natures (metals, ceramics, soils, concretes, etc.).

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