The back pressure in the stuffer box as a factor in the properties of textured polyamide yarn

1975 ◽  
Vol 6 (6) ◽  
pp. 660-663
Author(s):  
V. V. Mikhlina ◽  
V. I. Kotova ◽  
N. K. Tarasenko ◽  
M. P. Nosov ◽  
V. V. Shemyatovskii ◽  
...  
Keyword(s):  
Back Pressure ◽  
Polyamide Yarn

Re-Dispersion of Flocculated Nanoparticles Using Back Pressure Valve with Small Orifice Channel

2014 ◽  
Vol 2 ◽  
pp. 78-81
Author(s):  
Nobuaki Aoki ◽  
Noriyoshi Manabe ◽  
Tadafumi Adschiri
Keyword(s):  
Back Pressure

Routing Optimization with Efficient Second Order Distributed Approach Using Congestion Control Rules

2017 ◽  
Vol 7 (7) ◽  
pp. 363
Author(s):  
Jaya Pratha Sebastiyar ◽  
Martin Sahayaraj Joseph
Keyword(s):  
Congestion Control ◽  
Second Order ◽  
Back Pressure ◽  
Order Method ◽  
Delay Performance ◽  
Routing Optimization ◽  
Distributed Approach ◽  
Control Rules ◽  
Primal Dual ◽  
Queue Stability

Distributed joint congestion control and routing optimization has received a significant amount of attention recently. To date, however, most of the existing schemes follow a key idea called the back-pressure algorithm. Despite having many salient features, the first-order sub gradient nature of the back-pressure based schemes results in slow convergence and poor delay performance. To overcome these limitations, the present study was made as first attempt at developing a second-order joint congestion control and routing optimization framework that offers utility-optimality, queue-stability, fast convergence, and low delay.  Contributions in this project are three-fold. The present study propose a new second-order joint congestion control and routing framework based on a primal-dual interior-point approach and established utility-optimality and queue-stability of the proposed second-order method. The results of present study showed that how to implement the proposed second-order method in a distributed fashion.

Experimental research on the performance of the forward variable area bypass injector for variable cycle engines

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Binglong Zhang ◽  
He Liu ◽  
Jianhua Zhou ◽  
Hui Liu
Keyword(s):  
Pressure Ratio ◽  
Effective Means ◽  
Experimental System ◽  
Area Ratio ◽  
Back Pressure ◽  
Mode Transition ◽  
Bypass Valve ◽  
Injection Coefficient ◽  
Bypass Ratio ◽  
Specific Working

AbstractThe forward variable area bypass injector (FVABI) is a key component of double bypass variable cycle engine (VCE) to achieve mode transition and bypass ratio adjustment. In this paper, an experimental system for FVABI was constructed based on the analysis of relevant experimental theories, and then the experiments on FVABI were carried out for a specific working state in double bypass mode of VCE and for the comparison working states with different area ratios and different back pressure ratios. The results showed that the FVABI designed in this paper meets the requirements of VCE at this working state. The analysis of the influence of area ratio and back pressure ratio on the injection coefficient showed that the first bypass valve and back pressure were effective means to control the mass flow of FVABI.

scholarly journals Cavitation patterns in high-pressure homogenization nozzles with cylindrical orifices: Influence of mixing stream in Simultaneous Homogenization and Mixing

2021 ◽  
Author(s):  
V. Gall ◽  
E. Rütten ◽  
H. P. Karbstein
Keyword(s):  
High Pressure ◽  
Process Design ◽  
High Speed ◽  
State Of The Art ◽  
Back Pressure ◽  
High Pressure Homogenization ◽  
Unit Operation ◽  
Mixing Chamber ◽  
Cavitation Intensity ◽  
Droplet Sizes

AbstractHigh-pressure homogenization is the state of the art to produce high-quality emulsions with droplet sizes in the submicron range. In simultaneous homogenization and mixing (SHM), an additional mixing stream is inserted into a modified homogenization nozzle in order to create synergies between the unit operation homogenization and mixing. In this work, the influence of the mixing stream on cavitation patterns after a cylindrical orifice is investigated. Shadow-graphic images of the cavitation patterns were taken using a high-speed camera and an optically accessible mixing chamber. Results show that adding the mixing stream can contribute to coalescence of cavitation bubbles. Choked cavitation was observed at higher cavitation numbers σ with increasing mixing stream. The influence of the mixing stream became more significant at a higher orifice to outlet ratio, where a hydraulic flip was also observed at higher σ. The decrease of cavitation intensity with increasing back-pressure was found to be identical with conventional high-pressure homogenization. In the future, the results can be taken into account in the SHM process design to improve the efficiency of droplet break-up by preventing cavitation or at least hydraulic flip.

scholarly journals Latency-Optimal Computational Offloading Strategy for Sensitive Tasks in Smart Homes

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2347
Author(s):  
Yanyan Wang ◽  
Lin Wang ◽  
Ruijuan Zheng ◽  
Xuhui Zhao ◽  
Muhua Liu
Keyword(s):  
Queue Length ◽  
Optimization Problem ◽  
Time Slot ◽  
Smart Homes ◽  
Back Pressure ◽  
Smart Devices ◽  
Smart Device ◽  
Simulation Results ◽  
Computational Offloading ◽  
The Stability

In smart homes, the computational offloading technology of edge cloud computing (ECC) can effectively deal with the large amount of computation generated by smart devices. In this paper, we propose a computational offloading strategy for minimizing delay based on the back-pressure algorithm (BMDCO) to get the offloading decision and the number of tasks that can be offloaded. Specifically, we first construct a system with multiple local smart device task queues and multiple edge processor task queues. Then, we formulate an offloading strategy to minimize the queue length of tasks in each time slot by minimizing the Lyapunov drift optimization problem, so as to realize the stability of queues and improve the offloading performance. In addition, we give a theoretical analysis on the stability of the BMDCO algorithm by deducing the upper bound of all queues in this system. The simulation results show the stability of the proposed algorithm, and demonstrate that the BMDCO algorithm is superior to other alternatives. Compared with other algorithms, this algorithm can effectively reduce the computation delay.

scholarly journals Computer approximation of air gauge dynamic characteristics using the sine input test rig

2019 ◽  
Vol 252 ◽  
pp. 02002
Author(s):  
Michał Jakubowicz ◽  
Mirosław Rucki ◽  
Zbigniew Siemiątkowski
Keyword(s):  
Dynamic Error ◽  
Calibration Procedure ◽  
Back Pressure ◽  
Test Rig ◽  
Process Measurement ◽  
Dynamical Characteristics ◽  
Full Control ◽  
Circular Frequency ◽  
Measuring Signal ◽  
Input Test

The paper describes the test rig dedicated for air gauge dynamical characteristics assessment. The computerised system enables measurement of the amplitudes of back-pressure pk dependent on the input signal circular frequency ω. Dedicated software performs full control on the calibration procedure, which consists of setting a rotational speed and registration of measuring signal, and further data processing. Circular frequency ω was gradually changed with the appropriate step, in order to obtain a series of frequencies in the range from 0.1 to 20 Hz. The response of a measurement system was registered as a sinusoidal curve which after smoothening and interpolation procedures provided an amplitude-frequency graph with its main characteristics, such as time constant and the frequency f0.95 that generated dynamic error 5%. It was demonstrated that sine input dynamic calibration corresponds with real conditions of the in-process measurement with air gauges.

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