Real Time Flow Control System for Precise Gas Feed in COIL

This paper reports development of a real time flow control system for precise, controlled and uniform gas feed to a flowing medium Chemical Oxygen Iodine Laser (COIL). The optimal operation of this prominent laser depends upon the desired supply of gas constituents such as nitrogen (N2), chlorine (Cl2) and iodine (I2) to achieve adequately mixed laser gas. The laser also demands real time variation of flow rates during gas constituent transitions in order to maintain stabilized pressures in critical subsystems. Diluent nitrogen utilized for singlet oxygen transport is termed as primary buffer gas and that for iodine transport is termed as secondary buffer gas (with main and bypass components). Also, nitrogen in precise flows is used for mirror blowing, nozzle curtain, cavity bleed and diffuser startup. A compact hybrid data acquisition system (Hybrid DAS) for precise flow control using LabVIEW 2014 platform has been developed. The supported flow ranges may vary from few mmole.s-1 to few hundred mmole.s-1. The estimated relative uncertainty in the largest gas component i.e. primary buffer gas feed is nearly 0.7%. The implementation of in-operation variation using flow ramp enables swift stabilization of singlet oxygen generator pressures critical for successful COIL operation. The performance of Hybrid DAS is at par with fully wired DAS providing the crucial benefit of remote field operation at distances of nearly 80m in line of sight and 35m with obstacles

Улучшение подъемных характеристик крыла со сверхкритическим профилем при использовании модулированного импульсного струйного актуатора

In this experimental investigation, a pulse flow control system on a high-lift device of a wing with a NASA SC(2)-0714 airfoil within the Reynolds number range of the take-off and landing phases, is proposed. In this study, an innovative method of signal modulation has been used in order to simultaneously exploit the benefits of both low and high excitation frequencies in one actuator driving signal that are known to be effective in separation control. It is observed that the lift and drag coefficients are improved due to the use of modulated pulse jets compared to the simple pulse jet.

An Automated Aerosol Collection and Extraction System to Characterize Electronic Cigarette Aerosols

Electronic cigarette (e-cigarette) market increased by 122% during 2014–2020 and is expected to continue growing rapidly. Despite their popularity, e-cigarettes are known to emit dangerous levels of toxic compounds (e.g., carbonyls), but a lack of accurate and efficient testing methods is hindering the characterization of e-cigarette aerosols emitted by a wide variety of e-cigarette devices, e-liquids, and use patterns. The aim of this study is to fill this gap by developing an automated E-cigarette Aerosol Collection and Extraction System (E-ACES) consisting of a vaping machine and a collection/extraction system. The puffing system was designed to mimic e-cigarette use patterns (i.e., power output and puff topography) by means of a variable power-supply and a flow control system. The sampling system collects e-cigarette aerosols using a combination of glass wool and a continuously wetted denuder. After the collection stage, the system is automatically washed with absorbing and extracting liquids (e.g., methanol, an acetaldehyde-DNPH solution). The entire system is controlled by a computer. E-ACES performance was evaluated against conventional methods during measurements of nicotine and carbonyl emissions from a tank type e-cigarette. Nicotine levels measured using glass fiber filters and E-ACES were not significantly different: 201.2 ± 6.2 and 212.5 ± 17 μg/puff (p = 0.377), respectively. Differences in formaldehyde and acetaldehyde levels between filter-DNPH cartridges and the E-ACES were 14% (p = 0.057) and 13% (p = 0.380), respectively. The E-ACES showed reproducible nicotine and carbonyl testing results for the selected e-cigarette vaping conditions.

Optimization Design of Centrifugal Pump Flow Control System Based on Adaptive Control

In this paper, in order to improve the control characteristics of the centrifugal pump flow control system, a mathematical model of the centrifugal pump flow control system was established based on an analysis of the basic structures, such as the frequency converter, motor, and centrifugal pump. Based on the adaptive control theory, the recursive least squares algorithm with a forgetting factor was used to estimate the real-time parameters of the centrifugal pump control system, and the self-tuning PID control method was used to optimize the mathematical model of the centrifugal pump flow control system. The simulation results showed that the adjustment time of the optimized system was shortened by 16.58%, and the maximum overshoot was reduced by 83.90%, which improved the rapidity and stability of the transient response of the system. This showed that adaptive control had a significant effect on improving the robustness and anti-interference ability of the centrifugal pump control system. In order to further verify the accuracy of the self-tuning PID control method, a flow adaptive control system test platform was built. The test results showed that under the conditions of constant frequency and variable frequency, the actual flow rate of the centrifugal pump was always kept near the set flow rate, the error was small, and it had better real-time followability. The research results showed that adaptive control could revise the parameters in real-time according to changes to the centrifugal pump control system, which improved the stability and robustness of the system. Therefore, adaptive PID control could effectively improve the adaptability of centrifugal pumps to various complex working conditions and improve the working efficiency of centrifugal pumps.

Stability Analysis of Nonlinear Glue Flow Control System With Delay

In this paper, we improve a new mathematical model associated with glue flow control system for glue applying of particleboard. Firstly, we study the existence and stability of the equilibria and the existence of fold, Hopf and Bogdanov-Takens bifurcations in above system. Next, the normal forms of Hopf bifurcation and Bogdanov-Takens bifurcation are derived, and the classifications of local dynamics near above bifurcation critical values are analyzed. Then, numerical simulation results show that the flow control system associated with glue applying of particleborad exists stable equilibrium, stable periodic-1, periodic-2, and periodic-4 solutions, and chaotic attractor phenomenon from a sequence of period-doubling bifurcations. Finally, we compare the dynamical phenomena of flow control system with and without cubic terms, showing that cubic terms can effect the dynamical behaviors of flow control system.

Implementasi Sensor Water Level Dalam Sistem Pengatur Debit Air Di Pesawahan

– he very rapid development of Information and Communication Technology (ICT) has an impact on all human activities today. The number of assistive media created by technology in agriculture has begun to emerge, apart from facilitating human work, the creation of these tools is considered to be able to shorten time and make harvests easier and faster. Many problems arise from farmers, especially in the problem of managing the waters for rice fields, one of which is when water does not flow from the springs, causing the rice fields to dry up and make rice and other plants die. The need for a technological innovation that functions as a water flow control system in rice field using a water level sensor that is applied with electronic programs and components, namely Arduino, is considered to be more effective, so that the irrigation system in paddy fields can be controlled and help solve the difficulties that occur.Keywords : water Level Sensor, ArduinoAbstrak- Perkembangan Teknologi Informasi dan Komunikasi (TIK) yang sangat pesat memberikan pengaruh terhadap segala aktivitas manusia saat ini . Banyaknya media alat bantu yang tercipta dari teknologi dalm bidang pertanian mulai bermunculan, selain mempermudah pekerjaan manusia, terciptanya alat tersebut dianggap dapat mempersingkat waktu dan membuat hasil panen lebih mudah dan lebih cepat. Banyak permasalahan yang muncul dari para petani, khususnya dalam permasalah pengurusan perairan untuk pesawahan salah satunya adalah ketika air tidak mengalir dari mata air sehingga menyebabkan pesawahan akan mengering dan membuat tumbuhan padi dan tumbuhan lainnya akan mati. Perlunya sebuah inovasi teknologi yang berfungsi sebagai sistem pengatur debit air di sawahan menggunakan sensor water level yang di aplikasi dengan program dan komponen elektronika yaitu arduino dianggap akan lebih efektif, sehingga sistem pengairan di pesawahan dapat di control serta membantu menyelesaikan kesulitan yang terjadi. Kata Kunci : sensor water level , Arduino