Physical Model for Real-Time Simultaneous Estimation of Intake Mass and Cylinder Pressure in an SI Engine

2016 ◽  
Author(s):  
Shuonan Xu ◽  
Zhe Wang ◽  
Robert Prucka ◽  
Zoran Filipi ◽  
Michael Prucka ◽  
...  
Keyword(s):  
Real Time ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Air Flow ◽  
Estimation Algorithm ◽  
Simultaneous Estimation ◽  
Cylinder Pressure ◽  
Pressure Transducers ◽  
Prediction Techniques

Stringent emission regulations require spark ignited (SI) engines to operate at stoichiometry to enable the use of a three way catalyst (TWC). Thus, accurate prediction of the intake charge mass flow rate is paramount. Current speed-density air mass-flow prediction techniques require extensive calibration for predicting volumetric efficiency, while mass air flow (MAF) meter based approaches suffer from a loss of accuracy during transients. This work aims to provide an alternative, i.e. a model based air charge estimation algorithm that can reduce calibration effort and provide a universal solution across engine platforms. An additional objective is to minimize the number of required sensors and associated cost. The foundation is established with a 0-D physics-based air charge model, where air flow through intake and exhaust valves is modeled on a crank-angle basis, without the need to measure in-cylinder pressure. The proposed algorithm solves differential equations for cylinder pressure and mass flow rate in/out of the cylinder to simultaneously obtain instantaneous pressure and mass-flow estimations, hence eliminating the need to install cylinder pressure transducers. An additional benefit is the robustness of the new model, due to its ability to self-compensate for an error in the intake runner pressure or initial estimation of the cylinder pressure. The model has been validated with GT-Power simulations and steady-state engine tests with multiple actuator sweeps. Transient tests and real-time implementations were performed as well.

scholarly journals Dynamic Modelling and Simulation of a Multistage Flash Desalination System

Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 522
Author(s):  
Qiu-Yun Huang ◽  
Ai-Peng Jiang ◽  
Han-Yu Zhang ◽  
Jian Wang ◽  
Yu-Dong Xia ◽  
...  
Keyword(s):  
Real Time ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Dynamic Change ◽  
Seawater Temperature ◽  
Dynamic Modelling ◽  
Optimal Operation ◽  
Simultaneous Solution ◽  
Time Optimal

As the leading thermal desalination method, multistage flash (MSF) desalination plays an important role in obtaining freshwater. Its dynamic modeling and dynamic performance prediction are quite important for the optimal control, real-time optimal operation, maintenance, and fault diagnosis of MSF plants. In this study, a detailed mathematical model of the MSF system, based on the first principle and its treatment strategy, was established to obtain transient performance change quickly. Firstly, the whole MSF system was divided into four parts, which are brine heat exchanger, flashing stage room, mixed and split modulate, and physical parameter modulate. Secondly, based on mass, energy, and momentum conservation laws, the dynamic correlation equations were formulated and then put together for a simultaneous solution. Next, with the established model, the performance of a brine-recirculation (BR)-MSF plant with 16-stage flash chambers was simulated and compared for validation. Finally, with the validated model and the simultaneous solution method, dynamic simulation and analysis were carried out to respond to the dynamic change of feed seawater temperature, feed seawater concentration, recycle stream mass flow rate, and steam temperature. The dynamic response curves of TBT (top brine temperature), BBT (bottom brine temperature), the temperature of flashing brine at previous stages, and distillate mass flow rate at previous stages were obtained, which specifically reflect the dynamic characteristics of the system. The presented dynamic model and its treatment can provide better analysis for the real-time optimal operation and control of the MSF system to achieve lower operational cost and more stable freshwater quality.

Electrostatic Sensor for Real–Time Mass Flow Rate Measurement of Particle Conveying in Pneumatic Pipeline

2012 ◽  
Author(s):  
Mohd. Fua’ad Rahmat ◽  
Wee Lee Yaw
Keyword(s):  
Real Time ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Cross Correlation ◽  
High Accuracy ◽  
Industrial Processes ◽  
Rate Measurement ◽  
Flow Rate Measurement ◽  
Controlled Flow

This paper discussed the electrostatic sensors that have been constructed for real–time mass flow rate measurement of particle conveying in a Pneumatic pipeline. Many industrial processes require continuous, smooth, and consistent delivery of solids materials with a high accuracy of controlled flow rate. This requirement can only be achieved by installing a proper measurement system. Electrostatic sensor offers the most inexpensive and simplest means of measuring solids flows in pipes. Key words: Electrostatic sensor, cross-correlation, peripheral velocity

Condensation-Induced Water Hammer in Horizontal Refrigerant Pipe With Warm Gas Entry

2003 ◽  
Author(s):  
C. Samuel Martin
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
High Speed ◽  
Fast Response ◽  
Ammonia Gas ◽  
Pressure Transducers ◽  
High Speed Data Acquisition ◽  
High Speed Data ◽  
Liquid Depth

Careful experiments have been conducted for the purpose of investigating the phenomenon of condensation-induced waterhammer in an ammonia refrigeration system. To initiate a waterhammer event warm ammonia gas was introduced over static subcooled ammonia liquid placed in a horizontal 146.3 mm diameter carbon steel pipe 6.0 m in length. By means of fast response piezoelectric pressure transducers and a high speed data acquisition system rapid dynamic pressures were recorded whenever a shock event occurred. The occurrence of condensation-induced waterhammer depended upon three major variables; namely, (1) initial liquid depth, (2) liquid temperature, and (3) mass flow rate of warm gas. For given liquid depth and temperature, once the warm gas threshold conditions were exceeded shocks occurred with greater magnitude as the mass flow rate of gas input was increased. With adequate subcooling condensation-induced waterhammer occurred for initial liquid depths ranging from 25% to 95% of internal pipe diameter. The threshold mass flow rate of warm gas necessary to initiate waterhammer was greater as the initial liquid was lowered.

Design and Optimization of the Restrictor of a Race Car

2015 ◽  
Author(s):  
Prithvi Raj Kokkula ◽  
Shashank Bhojappa ◽  
Selin Arslan ◽  
Badih A. Jawad
Keyword(s):  
Fluid Dynamics ◽  
Pressure Drop ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Air Flow ◽  
Intake Manifold ◽  
Maximum Pressure ◽  
Cross Sectional ◽  
Formula Sae

Formula SAE is a student competition organized by SAE International. The team of students design, manufacture and race a car. Restrictions are imposed by the Formula SAE rules committee to restrict the air flow into the intake manifold by putting a single restrictor of 20 mm. This rule limits the maximum engine power by reducing the mass flow rate flowing to the engine. The pull is greater at higher rpms and the pressure created inside the cylinder is low. As the diameter of the flow path is reduced, the cross sectional area for flow reduces. For cars running at low rpm when the engine requires less air, the reduction in area is compensated by accelerated flow of air through the restrictor. Since this is for racing purpose cars here are designed to run at very high rpms where the flow at the throat section reach sonic velocities. Due to these restrictions the teams are challenged to come up with improved restrictor designs that allow maximum pressure drop across the restrictor’s inlet and outlet. The design considered for optimizing a flow restrictor is a venturi type having 20 mm restriction between the inlet and the outlet complying with the rules set by Formula SAE committee. The primary objective of this work is to optimize the flow restriction device that achieves maximum mass flow and minimum pull from the engine. This implies the pressure difference created due to the cylinder pressure and the atmospheric pressure at the inlet should be minimum. An optimum flow restrictor is designed by conducting analysis on various converging and diverging angles and coming up with an optimum value. Venturi type is a tubular pipe with varying diameter along its length, through which the fluid flows. Law of governing fluid dynamics states that the “Velocity of the fluid increases as it passes through the constriction to satisfy the principle of continuity”. An equation can be derived from the combination of Bernoulli’s equation and Continuity equation for the pressure drop due to venturi effect. [1]. A Computational Fluid Dynamics (CFD) tool is used to calculate the minimum pressure drop across the restrictor by running a series of analysis on various converging and diverging angles and calculating the pressure drop. As a result, an optimum air flow restrictor is achieved that maximizes the mass flow rate and minimizes the engine pull.

scholarly journals Performance of solar dryer chamber used for convective drying of sponge-cotton

2014 ◽  
Vol 18 (suppl.2) ◽  
pp. 451-462 ◽  
Author(s):  
Walid Aissa ◽  
Mostafa El-Sallak ◽  
Ahmed Elhakem
Keyword(s):  
Mass Flow Rate ◽  
Air Temperature ◽  
Mass Flow ◽  
Flow Rate ◽  
Air Flow ◽  
Ambient Air ◽  
Moisture Ratio ◽  
Convective Drying ◽  
Solar Dryer ◽  
Air Temperatures

Solar dryer chamber is designed and operated for five days of July 2008. Drying experiments are conducted for sponge-cotton; as a reference drying material in the ranges between 35.0 to 49.5?C of ambient air temperature, 35.2 to 69.8 ?C drying air temperature, 30 to 1258 W/m2 solar radiation and 0.016 to 0.08 kg/s drying air flow rate. For each experiment, the mass flow rate of the air remained constant throughout the day. The variation of moisture ratio, drying rate, overall dryer efficiency, and temperature distribution along the dryer chamber for various drying air temperatures and air flow rates are discussed. The results indicated that drying air temperature is the main factor in controlling the drying process and that air mass flow rate has remarkable influence on overall drying performance. For the period of operation, the dryer attained an average temperature of 53.68?C with a standard deviation of 8.49?C within a 12-h period from 7:00 h to 19:00 h. The results of this study indicated that the present drying system has overall efficiency between 1.85 and 18.6 % during drying experiments. Empirical correlations of temperature lapse and moisture ratio in the dryer chamber are found to satisfactorily describe the drying curves of sponge-cotton material which may form the basis for the development of solar dryer design charts.

scholarly journals Near-Real-Time Detection of Tephra Eruption Onset and Mass Flow Rate Using Microwave Weather Radar and Infrasonic Arrays

2016 ◽  
Vol 54 (11) ◽  
pp. 6292-6306 ◽  
Author(s):  
Frank S. Marzano ◽  
Errico Picciotti ◽  
Saverio Di Fabio ◽  
Mario Montopoli ◽  
Luigi Mereu ◽  
...  
Keyword(s):  
Real Time ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Weather Radar ◽  
Real Time Detection

Increasing Turbocharged Engine Operating Ranges Through Use of a Booster System

2007 ◽  
Author(s):  
Kirby S. Chapman ◽  
Ali Keshavar ◽  
Kyle Wolfram
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Pressure Ratio ◽  
Air Flow ◽  
Oxides Of Nitrogen ◽  
Ambient Conditions ◽  
Lean Burn ◽  
Ambient Temperatures ◽  
Natural Gas Industry

In the natural gas industry a large portion of the engines used for compression are lean-burn engines. When these engines operate at low equivalence ratios, oxides of nitrogen (NOX) can be minimized. The lean-burn engines are turbocharged to deliver high air flow to the engine. However, varying ambient temperatures alter the mass flow rate of air delivered to the engine, changing the equivalence ratio the engine fires at. This may cause an engine to be de-rated, or taken off line reducing the gas throughput. This problem can be partially offset by the installation of a turbocharger booster system to increase the available energy at the turbocharger turbine inlet. One method to boost the energy available to drive the turbocharger is to increase the temperature of the exhaust before it enters the turbine via a relatively small dry low NOX burner. A turbocharger booster system was designed, prototyped, installed, and tested at the National Gas Machinery Laboratory (NGML) turbocharger test and research facility (TTRF). The test data show that the addition of a turbocharger booster system increased the speed of the turbocharger without increasing the emission levels. The increase in speed translates to an increased pressure ratio and mass flow rate of air produced by the compressor. By controlling the booster system, constant air flow rate can be achieved regardless of ambient conditions. This paper provides test results that show how the system can be used to increase an engine’s operating range and mitigate ambient effects.

Hybrid Pressure-Swirl/Twin-Fluid Atomizer for Emission Controls

2006 ◽  
Author(s):  
Andrew C. S. Lee ◽  
Paul E. Sojka
Keyword(s):  
Flow Field ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Drop Size ◽  
Air Flow ◽  
Exit Plane ◽  
Swirl Atomizer ◽  
Pressure Swirl ◽  
Pressure Swirl Atomizer

An experimental study was conducted to characterize the performance of a hybrid atomizer used in emission control devices. Characterization included drop size distribution, measured using a forward light-scattering instrument, the air flow field (axial and radial velocities), measured using 2-D PIV, and turbulence characteristics of the air flow field, measured using LDA. The air flow field showed characteristics common to turbulent free round jets beyond approximately 8 exit orifice diameters from the atomizer exit plane. The centerline velocity increased with an increase in mass flow rate, while radial velocities were two orders of magnitude smaller than centerline values. The jet spreading factor initially increased with an increase in axial distance from the exit; however, it stabilized at a value of 0.09 at z/Do=11.8. Turbulence intensity along the jet centerline stabilized at 25% at z/Do=7.9. Drop size data showed complex dependencies on liquid and air mass flow rates, and on internal geometry. The influence of liquid mass flow rate on drop size was significantly smaller for the hybrid atomizer than for the pressure swirl atomizer component housed inside the hybrid unit, thus indicating a higher turndown ratio for the hybrid device. Drop size distributions produced by the hybrid atomizer showed multiple peaks, indicating there is more than one important atomizing mechanism. Finally, reducing the gap between the pressure-swirl atomizer and the exit plane of the outer casing resulted in a reduction in drop size.

Real time mass flow rate measurement using multiple fan beam optical tomography

2008 ◽  
Vol 47 (1) ◽  
pp. 3-14 ◽  
Author(s):  
R. Abdul Rahim ◽  
L.C. Leong ◽  
K.S. Chan ◽  
M.H. Rahiman ◽  
J.F. Pang
Keyword(s):  
Real Time ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Optical Tomography ◽  
Rate Measurement ◽  
Flow Rate Measurement

scholarly journals Thermal power of small scale manually fed boiler

2015 ◽  
Vol 19 (1) ◽  
pp. 329-340
Author(s):  
Todor Janic ◽  
Sasa Igic ◽  
Nebojsa Dedovic ◽  
Darijan Pavlovic ◽  
Jan Turan ◽  
...  
Keyword(s):  
Mass Flow Rate ◽  
Residence Time ◽  
Mass Flow ◽  
Flow Rate ◽  
Flue Gas ◽  
Air Flow ◽  
Thermal Power ◽  
Boiler Furnace ◽  
Flue Gas Recirculation ◽  
Gas Recirculation

This study reviews test results of the combustion of square soybean straw bales used as fuel in manually fed boiler with nominal thermal power of 120 kWth. The influence of the mass flow rate (180, 265, 350, 435, and 520 kg h-1) of inlet air and flue gas recirculation (0%, 16.5%, and 33%) fed to the boiler furnace was continuously monitored. Direct method was used for determination of the boiler thermal power. Correlation between boiler thermal power and bale residence time has been observed and simple empirical equation has been derived. General conclusions are as follows: the increase of the flow rate of inlet air passing through the boiler furnace results in decrease of the bale residence time and increase of the boiler thermal power. Share of the flue gas recirculation of 16.5% increases bale residence time and decreases average boiler thermal power in all regimes except in the regime with inlet air flow rate of 265 kg h-1. In regime with 0% flue gas recirculation boiler thermal power was higher than nominal in regimes with 435 and 520 kg h-1 inlet air flow rates. In regimes having inlet air mass flow rate of 350 kg h-1 boiler thermal power is equal to the nominal power of 120 kWth.

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