Fuel Flowrate Control for Aeroengine and Fuel Thermal Management for Airborne System of Aircraft—An Overview

Fuel flowrate control system and fuel thermal management are very important for aeroengine and the overall aircraft, and it has been researched for several decades. This survey paper makes a comprehensive and systematic overview on the exiting fuel flowrate regulation methods, thermal load of fuel metering units, fuel-based thermal management, and the fuel tank’s thermal management topology network with drain and recirculation. This paper firstly reviews the mechanism, technical advantages, and technical challenges of the fuel metering unit with flowrate control valve and constant pressure difference valve compensator, flowrate control valve and variable displacement pump-based pressure difference compensator, and motor-based flowrate regulation. Then, the technical characteristics of above fuel flowrate control methods related to thermal management are discussed and compared. Meanwhile, the behaviors of recirculated fuel flow within single tank system and dual tank system are explored. Thirdly, the paper discusses the future directions of fuel flowrate control and thermal management. The survey is significant to the fuel flowrate control and fuel thermal management of the aircraft.

A New Viscosity and Density Sensing Platform for Drilling Automation

During drilling operations, measurements of drilling fluid/mud viscosity and density provide key information to ensure safe operations (e.g., maintain wellbore integrity) and improve the rate of penetration (e.g., maintain proper hole cleaning). Nowadays, these measurements are still performed manually by using a calibrated funnel viscometer and a weight balance, as stipulated by current American Petroleum Institute (API) standards. In this study, we introduce an automated viscosity/density measurement system based on an electromechanical tuning fork resonator. The system allows for continuous measurements as fast as several times per second in a compact footprint, allowing it to be deployed in tanks or pipelines and/or gathering data from multiple sensors in the mud circulation system. The streams of data produced were broadcasted to a nearby computer allowing for live monitoring of the viscosity and density. The results obtained by the in-tank system in five wells were in good agreement with the standard reference measurements from the mud logs. Here, we describe the development and testing of the tool as well as general guidelines for integration into a rig edge-computing system for real-time analytics and detection of operational problems and drilling automation.

A simulation approach for closed-loop control of coupled four tank system

The coupled tank system is the most widely used sub-component in chemical process industries. Fluid mixing is a major step in chemical processes that alters the material properties and cost. Fluid flow and its level regulation between several tanks are important control problems. As the first step, this paper addresses the level regulation problem using classical integer order proportional, derivative, integral (PID), fractional order PID controllers. As a second step, model-based robust fractional order controllers are derived using sliding mode approach in order to achieve the desired response, parameters of the proposed controllers are tuned using genetic algorithm. Finally, system performance under all variants of control schemes has been tested using numerical simulations.

Diagnosing Systems through Approximated Information

This article presents a novel approach to diagnose faults in injection molding machines. A novel data-driven approach is presented to learn an approximation of dependencies between variables using Spearman correlation. It is further shown, how the approximation of the dependencies are used to create propositional logic rules for fault diagnosis. The article presents two novel algorithms: 1) to estimate dependencies from process data and 2) to create propositional logic diagnosis rules from those connections and perform consistency-based fault diagnosis. The presented approach was validated using three experiments. The first two show that the presented approach works well for injection molding machines and a simulation of a four-tank system. The limits of the presented method are shown with the third experiment containing sets of highly correlated signals.

Microbial and Physicochemical Qualities of Septic Tank Wastewater: An Evaluation.

The physicochemical and microbial qualities of septic tank effluent samples from households within the study area were evaluated. Three replicate samples from Locations A, B, and C representing Agbor, Benin City, and Sapele regions of Delta and Edo States, Nigeria were collected from both the inlet tank (raw sewage) and the outlet chamber (semi-treated sewage) for physicochemical and microbiological analyses using standard methods. Results of the physicochemical analyses showed that pH values ranged from 6.5 – 7.7 across locations and in both the raw and semi-treated samples. Electrical conductivity (EC), Total suspended solid (TSS) and BOD was significantly higher (p>0.05) in the raw sewage (RS) than in the semi-treated (SS), while DO was higher (p>0.05) in the SS in all three locations sampled. Microbial analysis shows that total heterotrophic bacteria (THB) was highest in the RS in two locations. Microbial isolates from wastewater samples included Staphylococcus aureus, Proteus mirabilis, Escherichia coli, Pseudomonas aeruginosa, and Aspergillus niger. DO was low at an average of 3.20 and 3.73 mg/L in both chambers of the septic tank. Average BOD5 of 59.4 and 42.8 mg/L and COD average of 206.8 and 153.2 mg/L were reported for the RS and SS chambers. 0.3 was the value of the ratio of BOD5/COD for the RS and SS in the study. This infers that biodegradation was slow and inefficient in the septic tank system, and that modification of the design is recommended to increase retention time in the RS chamber

A Comparative Study of Nonsingular Terminal Sliding Mode and Backstepping Schemes for the Coupled Two-Tank System

This paper presents an implementation of two radically different control schemes for a state-coupled two-tank liquid-level system. This is due to the purpose of transferring theoretical studies to industrial systems. The proposed schemes to be introduced and compared are the nonsingular terminal sliding mode control (NTSMC) and the backstepping control (BC). The performances of the developed methods are experimentally tested on a particular class of second-order nonlinear systems. The main purpose of the considered control schemes is to achieve a tracking trajectory for a coupled-tank system. It is proved that the designed robust controllers guarantee the stability of the corresponding closed loop systems. The obtained results are verified with the same setup test to ensure a suitable basis for their comparison. During the experiments, we resorted to adding an integrator to the backstepping control so that we improve the results, leading to the appearance of the integrator backstepping control (IBC). To focus on the adequacy and applicability of the suggested control layout, theoretical comparisons as well as experimental results are afforded and debated.