scholarly journals A model based new method for injection rate determination

2020 ◽  
pp. 159-159 ◽  
Author(s):  
Sándor Vass ◽  
Máté Zöldy

This paper presents a detailed model of a Common Rail Diesel injector and its validation using injection rate measurement. A new method is described for injector nozzle flowrate determination using simulation and measurement tools. The injector model contains fluid dynamic, mechanic and electro-magnetic systems, describing all-important internal processes and also includes the injection rate meter model. Injection rate measurements were made using the W. Bosch method, based on recording the pressure traces in a length of fuel during injections. Comparing the results of the simulated injection rate meter, simulated injector orifice flow and injection rate measurements, the simulated and measured injection rates showed good conformity. In addition to this, the difference between nozzle flow rate and the measured flow rate is pointed out in different operating points, proving, that the results of a Bosch type injection rate measurements cannot be directly used for model validation. However, combining injector, injection rate meter simulation and measurement data, the accurate nozzle flow rate can be determined, and the model validated.

Author(s):  
Sándor Vass ◽  
Máté Zöldy

Abstract This work is about the validation of a Common Rail (CR) injector model. The model describes injector internal behavior in a detailed way, validation is done using dosage measurements and needle lift traces. The model contains fluid dynamic, mechanic and electro-magnetic parts describing all important internal processes. To compare the modelling results against measurement data, three test cases were chosen on a medium duty test engine to represent a wide range of operation points. Dosage measurements were done by averaging the injected mass of 1500 injections, each measurement repeated three times. Needle displacement was measured using an injector equipped with a needle lift sensor in the same operating points. The results of the simulated injector and the measured values showed good conformity both in needle displacement and injected fuel mass, so the model can be a basis for further injector and combustion analyses.


Energies ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1444 ◽  
Author(s):  
Liang Sun ◽  
Baozhu Li ◽  
Hanqiao Jiang ◽  
Yong Li ◽  
Yuwei Jiao

Good polymer flood performance evaluation requires an understanding of polymer injectivity. Offshore reservoirs are characterized by unfavorable water–oil mobility ratios, strong heterogeneity, and multilayer production, which collectively contribute to unique challenges. Accordingly, this article presents a semi-analytical model for the evaluation of commingled and zonal injectivity in the entire development phase, which consists of primary water flooding, secondary polymer flooding, and subsequent water flooding. First, we define four flow regions with unique saturation profiles in order to accurately describe the fluid dynamic characteristics between the injector and the producer. Second, the frontal advance equation of polymer flooding is built up based on the theory of polymer–oil fractional flow. The fluid saturation distribution and the injection–production pressure difference are determined with the method of equivalent seepage resistance. Then, the zonal flow rate is obtained by considering the interlayer heterogeneity, and the semi-analytical model for calculating polymer injectivity in a multilayer reservoir is established. The laboratory experiment data verify the reliability of the proposed model. The results indicate the following. (1) The commingled injectivity decreases significantly before polymer breakthrough and increases steadily after polymer breakthrough. The change law of zonal injectivity is consistent with that of commingled injectivity. Due to the influence of interlayer heterogeneity, the quantitative indexes of the zonal flow rate and injection performance are different. The injectivity of the high-permeability layer is better than that of the low-permeability layer. (2) The higher the injection rate and the lower the polymer concentration, the better the injectivity is before polymer breakthrough. An earlier injection time, lower injection rate, larger polymer injection volume, and lower polymer concentration will improve the injectivity after polymer breakthrough. The polymer breakthrough time is a significant indicator in polymer flooding optimization. This study has provided a quick and reasonable model of injectivity evaluation for offshore multilayer reservoirs.


Author(s):  
Zhounian Lai ◽  
Peng Wu ◽  
Shuai Yang ◽  
Dazhuan Wu

In this paper, a model composed of pump and valves used to achieve flow rate regulation is built. A control strategy to improve reliability and efficiency of the pump-valve system is introduced. An optimizer and a controller are developed. The optimizer will calculate the pressure loss across the valve and the head of the pump to limit the operation point of the pump to nearby the design point. The controller manages the control of flow rate and the pressure loss across the valve. The controlled variables of the control system are flow rate and the pressure loss across the valve, the control variables are the speed of pump and the lift of valve. This makes the system a coupled nonlinear Multi-Input Multi-Output (MIMO) system. A differential geometry method is introduced to decouple the MIMO system. The result of the control strategy is shown in simulations. The difference between traditional PID method and the new method is compared. The result shows that the new method sacrifices power consumption for a better reliability. This paper provides an option to improve reliability of pump systems.


Transport ◽  
2021 ◽  
Vol 0 (0) ◽  
pp. 1-8
Author(s):  
Sandor Vass ◽  
Máté Zöldy

Spread and evolution of Common Rail (CR) injection systems enable to influence injection events more efficiently than ever, while injection mass flow rate during an injection event crucially affects the combustion process. A measurement device based on the work of Bosch was set up, and measurements were made with different boundary conditions to explore the capabilities of the measurement system and to validate a detailed model of a CR injector. The main finding of this research work is, that orifice size had no noticeable effect on the measured injection rate traces, while it was stated in the original work that a small orifice is needed to terminate the measuring tube to maintain stable measurement conditions. Moreover, the backpressure level in the measuring system has a significant effect on the measured injection traces. If pressure in the measuring tube is low, gradient at the injection rate rise is lower, while if the pressure is comparable with that of a combustion chamber maximal compression pressure, measurement of higher doses is unaccomplishable due to the long pressure decrease time in the measuring tube after the end of the injection. Based on the results of the investigation, it can be stated that the Bosch-type injection rate measurement method does not give back the exact injection rate shape, a supplementing method would be necessary to calculate real nozzle flow rate.


2012 ◽  
Vol 134 (6) ◽  
Author(s):  
Neerav Abani ◽  
Jaal B. Ghandhi

Turbulent starting jets with time-varying injection velocities were investigated using high-speed schlieren imaging. Two solenoid-controlled injectors fed a common plenum upstream of an orifice; using different upstream pressures and actuation times, injection-rate profiles with a step increase or decrease in injection velocity were tested. The behavior of the jet was found to be different depending on the direction of the injection-velocity change. A step increase in injection velocity resulted in an increased rate of penetration relative to the steady-injection case, and a larger increase in injection velocity resulted in an earlier change in the tip-penetration rate. The step-increase data were found to be collapsed by scaling the time by a convective time scale based on the tip location at the time of the injection-velocity change and the difference in the injection velocities. A sudden decrease in injection velocity to zero was found to cause a deviation from the corresponding steady-pressure case at a time that was independent of the initial jet velocity, i.e., it was independent of the magnitude of the injection-velocity change. Two models for unsteady injection from the literature were tested and some deficiencies in the models were identified.


2021 ◽  
pp. 1-24
Author(s):  
Rong Guo ◽  
Zanzan Sun ◽  
Zhen Huang ◽  
Rui Luo

Abstract Aiming at reducing the high-amplitude and wide-frequency noise in charged air intake system of the powertrain, this paper proposes a new method for predicting the acoustic characteristics of an irregular cross-section multi-chamber perforated resonator under flow conditions. By this method, the presence of three-dimensional sound waves and the effects of higher-order modes are considered, and the acoustic performance of the resonator can be evaluated through the computation of transmission loss. Moreover, by discretizing the cross-section of perforated resonator and extracting node information, this method can solve the acoustic characteristics of the perforated resonator with any cross-section. Based on the transfer matrix method, the quadrupole parameters of each chamber are obtained. Then the acoustic characteristics of the multi-chamber perforated resonator could be calculated. The theoretical prediction data and the experimental data have been compared and the results show good agreement within the entire frequency range, which verifies the accuracy of the theoretical prediction approach. Based on this prediction approach, the influence of section ratio, structure parameters and inlet flow rate on the acoustic characteristics of the resonator is explored. The results show that when the structural parameters change, the peak resonance frequency of the resonator will have a regular shift. With the increase of the inlet flow rate, the main frequency band of sound attenuation will decrease significantly. The theoretical method developed in this work can be used for the calculation and optimization of multi-chamber resonators in various applications.


2021 ◽  
Vol 1037 ◽  
pp. 227-232
Author(s):  
Nikita A. Zemlyanushnov ◽  
Nadezhda Y. Zemlyanushnova

The disadvantage of the known methods of hardening springs is the impossibility of their use when hardening springs of a conical shape or of a shape of a paraboloid of rotation, since they are intended only for cylindrical shape springs and are not suitable for conical shape springs or those of a shape of a paraboloid of rotation specifically because of the difference in the shape of the springs. One of the disadvantages of the known springs hardening mechanisms is the impossibility of hardening the inner surface of the conical compression springs. A new method of hardening springs is proposed, the unmatched advantage of which is the ability to create plastic deformations on the inner and outer surfaces of the spring coils compressed to contact and on the surfaces along the line of contact between the coils. A new advantageous mechanism for hardening springs is proposed, which makes it possible to harden the inner surface of compression springs having a conical shape or a paraboloid shape of rotation, in a compressed state.


Author(s):  
Randi Franzke ◽  
Simone Sebben ◽  
Emil Willeson

In this paper, a simplified underhood environment is proposed to investigate the air flow distribution in a vehicle-like set-up and provide high quality measurement data that can be used for the validation of Computational Fluid Dynamic methods. The rig can be equipped with two types of front openings representative for electrified vehicles. Furthermore, it is possible to install differently shaped blockages downstream of the fan to imitate large underhood components. The distance between the blockages and the fan can be varied in longitudinal and lateral direction. The measurements are performed with Laser Doppler Anemometry at a fixed distance downstream of the fan. The results show that the lack of an upper grille opening in the configuration for a battery electric vehicle has a notable impact on the flow field in the reference case without any downstream blockage. However, the differences in the flow field between the two front designs become less when a downstream obstruction is present. The longitudinal and lateral position of the blockages have a minor impact on the flow field compared to the shape of the obstacle itself.


Author(s):  
A. Stamatis ◽  
N. Aretakis ◽  
K. Mathioudakis

An approach for identification of faults in blades of a gas turbine, based on physical modelling is presented. A measured quantity is used as an input and the deformed blading configuration is produced as an output. This is achieved without using any kind of “signature”, as is customary in diagnostic procedures for this kind of faults. A fluid dynamic model is used in a manner similar to what is known as “inverse design methods”: the solid boundaries which produce a certain flow field are calculated by prescribing this flow field. In the present case a signal, corresponding to the pressure variation on the blade-to-blade plane, is measured. The blade cascade geometry that has produced this signal is then produced by the method. In the paper the method is described and applications to test cases are presented. The test cases include theoretically produced faults as well as experimental cases, where actual measurement data are shown to produce the geometrical deformations which existed in the test engine.


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