Dynamic Analysis of Airflow in Air-Jet Filling Insertion: Part I — Air Pressure Measurements

2002 ◽  
Author(s):  
Sayavur I. Bakhtiyarov ◽  
Sabit Adanur ◽  
Tacibaht Turel
Keyword(s):  
Dynamic Analysis ◽  
Textile Industry ◽  
Air Flow ◽  
Air Pressure ◽  
Experimental Measurements ◽  
Pressure Measurements ◽  
Pressure Losses ◽  
Air Jet

Air-jet filling insertion is the most used techniques in the textile industry. In this process the air flow provides the necessary propelling force to the yarn. Dynamic analysis of air flow in this process was studied experimentally in this work. In Part I we present the results of experimental measurements of pressure losses both in the tube-guided and in the profiled reed simulators.

Modelling of Air Flow in Impacted Polyurethane Foam

2002 ◽  
Vol 21 (5) ◽  
pp. 343-368 ◽  
Author(s):  
N.J. Mills ◽  
G. Lyn
Keyword(s):  
Stress Distribution ◽  
Flow Resistance ◽  
Air Flow ◽  
Air Pressure ◽  
Impact Response ◽  
Pressure Measurements ◽  
Uniform Stress ◽  
Total Stress ◽  
Difference Model ◽  
Made In

Polyurethane (PU) chip foam was characterised for air flow resistance, using a modification of the BS 4443 method, and for compressive impact response. A finite difference model was developed for the air flow in the impacted foam, including the effects of strain on foam permeability. It successfully predicted a non-uniform stress distribution across foam block of diameter > 100 mm, and showed that air flow is responsible for some but not all the hysteresis in this distribution for impact velocities > 3 m/s. Air pressure measurements, made in narrow vertical cavities inside impacted blocks of the foam, confirm the air pressure contribution to the total stress.

Dynamic Analysis of Airflow in Air-Jet Filling Insertion: Part II — Air Velocity Measurements

2002 ◽  
Author(s):  
Sabit Adanur ◽  
Sayavur I. Bakhtiyarov ◽  
Tacibaht Turel
Keyword(s):  
Dynamic Analysis ◽  
Air Flow ◽  
Flow Characteristics ◽  
Experimental System ◽  
Velocity Measurements ◽  
Air Velocity ◽  
Auburn University ◽  
Air Jet

Air-jet filling insertion is the most popular way of insertion systems in weaving. The heart of the air-jet filling insertion is the air flow, which provides the necessary propelling force for the yarn. In this work, the characteristics of airflow in air-jet filling insertion are discussed. The procedure and experimental system that is developed at Auburn University to measure the air flow characteristics is described.

An investigation of some parameter effects on the internal flow characteristics in the main nozzle

2016 ◽  
Vol 87 (1) ◽  
pp. 91-101 ◽  
Author(s):  
Yuzhen Jin ◽  
Jingyu Cui ◽  
Linhang Zhu ◽  
Peifeng Lin ◽  
Xudong Hu
Keyword(s):  
Flow Field ◽  
Textile Industry ◽  
Great Influence ◽  
Flow Characteristics ◽  
Internal Flow ◽  
Air Pressure ◽  
Weft Yarn ◽  
Internal Diameter ◽  
Air Jet ◽  
Air Jet Loom

The air-jet loom is widely used in the textile industry and the main nozzle is one of its key components. In this paper, the influence of some parameters, including the input air pressure and the structure of nozzle core and its internal diameter, on the internal flow field of the main nozzle is analyzed. Then the optimized structure of the main nozzle is proposed from the perspective of fluid dynamics. In the present simulations, the realizable [Formula: see text] model is applied to model the internal flow field of the main nozzle. The results show that the velocity in the annular throat reaches supersonic. Moreover, the pressure at the end of the nozzle core is the lowest in the main nozzle. It is also shown that the input air pressure has little effect on the axis velocity in Zone B, but on the other hand, has a great influence on the near-wall velocity field and the axis velocity in Zone C. In addition, an optimized structure of the nozzle core is proposed in this paper. It is found that with the proposed structure, the velocity boundary layer near the wall of Zone B in the accelerating tube can be well improved, and rapid diffusion of airflow in this area can be avoided. These help increase the moving speed of the weft yarn. Last but not least, we also show that decreasing of the internal diameter of the nozzle core improves the axis velocity of the weft accelerating tube. However, it brings a stronger turbulence at the same time.

Research on the motion law of fiber in the vortex field inside the nozzle based on ADINA fluid–structure coupling model

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Chenchen Han ◽  
Weidong Gao
Keyword(s):  
Air Flow ◽  
Three Dimensional ◽  
Coupling Model ◽  
Calculation Model ◽  
Air Pressure ◽  
Two Phase ◽  
Fluid Structure ◽  
Content Type ◽  
Air Jet ◽  
Vortex Field

PurposeThe purpose of the paper is researching on the motion law of fiber in the vortex field inside the nozzle.Design/methodology/approachA three-dimensional calculation model was established using the MVS861 (Muratec Vortex Spinning) air-jet vortex-spinning nozzle as the prototype, and the fluid–solid coupling calculation module in the finite element calculation software ADINA (Adina System) was used to numerically analyze the fiber-air flow two-phase coupling. At the same time, the effect of the air pressure at the nozzle on the two-phase flow is studied.FindingsThe results show that after the air flow ejected through the nozzle, a vortex field will be generated in the flow field to push the internal fiber to move toward the nozzle outlet in a wave motion; as the air pressure at the nozzle increases, the fiber movement period becomes shorter and the oscillation frequency becomes higher; increasing the air pressure at the spray hole can improve the working efficiency of fiber twisting and wrapping.Originality/valueThe research present an effective and feasible theoretical model and method for the motion law of fiber in the vortex field inside the nozzle based on ADINA fluid–structure coupling model.

Signal Interpretation Considerations When Estimating Subglottal Pressure From Oral Air Pressure

2019 ◽  
Vol 62 (5) ◽  
pp. 1326-1337 ◽  
Author(s):  
Brittany L. Perrine ◽  
Ronald C. Scherer ◽  
Jason A. Whitfield
Keyword(s):  
Standard Condition ◽  
Word Production ◽  
Air Pressure ◽  
Pressure Waveform ◽  
Pressure Measurements ◽  
Air Leak ◽  
Pressure Signal ◽  
Adult Participants ◽  
Syllable Repetition ◽  
Subglottal Pressure

Purpose Oral air pressure measurements during lip occlusion for /pVpV/ syllable strings are used to estimate subglottal pressure during the vowel. Accuracy of this method relies on smoothly produced syllable repetitions. The purpose of this study was to investigate the oral air pressure waveform during the /p/ lip occlusions and propose physiological explanations for nonflat shapes. Method Ten adult participants were trained to produce the “standard condition” and were instructed to produce nonstandard tasks. Results from 8 participants are included. The standard condition required participants to produce /pːiːpːiː.../ syllables smoothly at approximately 1.5 syllables/s. The nonstandard tasks included an air leak between the lips, faster syllable repetition rates, an initial voiced consonant, and 2-syllable word productions. Results Eleven oral air pressure waveform shapes were identified during the lip occlusions, and plausible physiological explanations for each shape are provided based on the tasks in which they occurred. Training the use of the standard condition, the initial voice consonant condition, and the 2-syllable word production increased the likelihood of rectangular oral air pressure waveform shapes. Increasing the rate beyond 1.5 syllables/s improved the probability of producing rectangular oral air pressure signal shapes in some participants. Conclusions Visual and verbal feedback improved the likelihood of producing rectangular oral air pressure signal shapes. The physiological explanations of variations in the oral air pressure waveform shape may provide direction to the clinician or researcher when providing feedback to increase the accuracy of estimating subglottal pressure from oral air pressure.

scholarly journals Geometrical Optimization of a Venturi-Type Microbubble Generator Using CFD Simulation and Experimental Measurements

Designs ◽  
2021 ◽  
Vol 5 (1) ◽  
pp. 4
Author(s):  
Dillon Alexander Wilson ◽  
Kul Pun ◽  
Poo Balan Ganesan ◽  
Faik Hamad
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
Cfd Simulation ◽  
Air Flow ◽  
Bubble Diameter ◽  
Diameter Ratio ◽  
Experimental Measurements ◽  
Cfd Model ◽  
Flow Rates ◽  
Throat Diameter

Microbubble generators are of considerable importance to a range of scientific fields from use in aquaculture and engineering to medical applications. This is due to the fact the amount of sea life in the water is proportional to the amount of oxygen in it. In this paper, experimental measurements and computational Fluid Dynamics (CFD) simulation are performed for three water flow rates and three with three different air flow rates. The experimental data presented in the paper are used to validate the CFD model. Then, the CFD model is used to study the effect of diverging angle and throat length/throat diameter ratio on the size of the microbubble produced by the Venturi-type microbubble generator. The experimental results showed that increasing water flow rate and reducing the air flow rate produces smaller microbubbles. The prediction from the CFD results indicated that throat length/throat diameter ratio and diffuser divergent angle have a small effect on bubble diameter distribution and average bubble diameter for the range of the throat water velocities used in this study.

Parametric study on pressure-based packed bed adsorption system for air dehumidification

2021 ◽  
pp. 095440892110073
Author(s):  
V Sureshkannan ◽  
TV Arjunan ◽  
D Seenivasan ◽  
SP Anbuudayasankar ◽  
M Arulraj
Keyword(s):  
Genetic Algorithm ◽  
Taguchi Method ◽  
Flow Rate ◽  
Uptake Rate ◽  
Air Flow ◽  
Packed Bed ◽  
Air Pressure ◽  
Dew Point ◽  
Adsorption System ◽  
Air Flow Rate

Compressed air free from traces of water vapour is vital in many applications in an industrial sector. This study focuses on parametric optimization of a pressure-based packed bed adsorption system for air dehumidification through the Taguchi method and Genetic Algorithm. The effect of operational parameters, namely absolute feed air pressure, feed air linear velocity, and purge air flow rate percent on adsorption uptake rate of molecular sieve 13X-water pair, are studied based on L25 orthogonal array. From the analysis of variance, it has been found that absolute feed air pressure and purge air flow rate percent were the parameters making significant improvement in the adsorption uptake rate. A correlation representing the process was developed using regression analysis. The optimum adsorption conditions were obtained through the Taguchi method and genetic algorithm and verified through the confirmation experiments. This system can be recommended for the industrial and domestic applications that require product air with the dew point temperature below 0°C.

Fluid mechanical aspects of open- and closed-toe flue organ pipe voicing

2011 ◽  
Vol 2 (2) ◽  
pp. 284-295
Author(s):  
D. Steenbrugge
Keyword(s):  
Pressure Measurements ◽  
Jet Instability ◽  
Active Involvement ◽  
Air Jets ◽  
Air Jet ◽  
Hole Area ◽  
Power Regulation ◽  
Organ Pipes ◽  
Organ Pipe ◽  
Jet Characteristics

Open- and closed-toe voicing of flue organ pipes constitute two opposite extremes of possible ways todetermine the air-jet flow rate through the flue. The latter method offers more voicing control parametersand thus more flexibility, at the expense of a necessary pressure loss at the toe hole. Another differencebetween both cases arises from different air-jet characteristics, such as velocity profile, Re number, flowmomentum or aspect ratio, the latter influencing jet instability. Furthermore, for closed-toe voicing, the flowfield in the pipe foot is modified by an axisymmetric air jet created through the highly constricted toe hole.Velocity measurements on air jets, pressure measurements in the pipe foot are presented, compared anddiscussed for both voicing methods. The ratio of flue to toe hole area is shown to be the sole pipeparameter to entirely determine the jet velocity and can be useful to quantitatively characterize flue and toehole voicing. Open-toe voicing turns out to be the more delicate and low-pressure only method becauseany modification of the flue has consequences on all aspects of the pipe operation, whereas the closed-toemethod, in connection with higher pressures and with active involvement of cut-up adjustment, allows someseparation between sound timbre and power regulation.

Oral Air Pressure and Nasal Air Flow Rate on Levator Veli Palatini Muscle Activity in Patients Wearing a Speech Appliance

1995 ◽  
Vol 32 (5) ◽  
pp. 382-389 ◽  
Author(s):  
Takashi Tachimura ◽  
Hisanaga Hara ◽  
Takeshi Wada
Keyword(s):  
Flow Rate ◽  
Muscle Activity ◽  
Neural Control ◽  
Air Flow ◽  
Air Pressure ◽  
Electromyographic Activity ◽  
Air Flow Rate ◽  
Circular Area ◽  
Pharyngeal Bulb ◽  
Levator Veli Palatini

This study was designed to determine if levator veli palatini muscle activity can be elicited by simultaneous changes in oral air pressure and nasal air flow when a speech appliance is in place. The speech appliances routinely worn by 15 subjects were each modified experimentally by drilling a hole in the vertical center of the pharyngeal bulb. The air flow rate into the nasal cavity through the opening in the bulb was altered by changing the circular area of the opening in the bulb from the occluded condition (Condition I), to circular area of 12.6 mm2 (4 mm in diameter; Condition II), and then to 38.5 mm2 (7 mm in diameter; Condition III). Electromyographic activity was measured from the levator veli palatini muscle with changes in nasal air flow rate and oral air pressure. Levator veli palatini muscle activity was correlated with changes in nasal air flow and oral air pressure. Increases in levator veli palatini muscle activity were associated with increases in nasal air flow rate compared to oral air pressure changes. The results indicated that aerodynamic variables of nasal air flow and oral air pressure might be involved in the neural control of speech production in individuals wearing a speech appliance, even if the subjects exhibit velopharyngeal incompetence without using a speech appliance. Also, the stimulating effect of bulb reduction therapy on velopharyngeal function might be achieved through the change in aerodynamic variables in association with the bulb reduction.

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