Semiempirical Analysis of Fuel-Air Ratio Distribution Downstream of a Plain Orifice Injector Under Nonuniform Crossflow

1986 ◽  
Vol 108 (1) ◽  
pp. 204-208
Author(s):  
J. S. Chin ◽  
W. M. Li ◽  
M. H. Cao

The present paper is a step further and a modification of the semiempirical analysis of liquid fuel distribution downstream of a plain orifice injector proposed previously [1]. It has been improved from the previous paper in two aspects: (i) the use of experimental data of plain orifice atomization under crossflow obtained by the present authors instead of using Ingebo’s correlation [2], and (ii) consideration taken of the effect of a nonuniform crossflow. The agreement between the calculated results and the experimental data on fuel-air ratio distribution is quite good. In particular the model is capable of predicting the maximum value of the fuel-air ratio distribution and its position. The model has been used for the calculation of fuel-air ratio distribution under nonuniform crossflow with different average flow velocities. Thus the authors are able to predict how the position of maximum fuel-air ratio changes with average velocity for the same profile. The results are in good agreement with the experimental data. From the results of present research the authors conclude that for fuel-air ratio prediction in afterburners or ramjets, it is necessary to consider the effects of nonuniform crossflow. The present semiempirical analysis provides a good design tool for combustor development.

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
Eduard Amromin

Cavitation within regions of flow separation appears in drifting vortices. A two-part computational method is employed for prediction of cavitation inception number there. The first part is an analysis of the average flow in separation regions without consideration of an impact of vortices. The second part is an analysis of equilibrium of the bubble within the core of a vortex located in the turbulent flow of known average characteristics. Computed cavitation inception numbers for axisymmetric flows are in the good agreement with the known experimental data.


2004 ◽  
Vol 18 (17n19) ◽  
pp. 2585-2589 ◽  
Author(s):  
HAI-LONG AN ◽  
YONG ZHAN ◽  
JIN-WEI LIU ◽  
SU-HUA ZHANG ◽  
TONG-JUN ZHAO

In this paper, by introducing the collision model of the K ion channel, the maximum value of ions inward the channel per second, the average velocity of ions in the channels and the average time of every ion passing through the channel are obtained. Moreover they are reconciled with the experimental data. Base on the experimental data, the empiristic potential function is deduced. With the Monte–Carlo simulation, the curve of average velocity versus time and average displacement versus time are calculated by resolving the over-damping Langevin equation with Gaussian-white noise. They are according with the experimental dada well.


2021 ◽  
Vol 286 ◽  
pp. 01008
Author(s):  
Saleh J. Alqaisy ◽  
Kamel S. Hmood ◽  
Mahdi Hatf Kadhum Aboaltabooq ◽  
Valentin Apostol ◽  
Horatiu Pop ◽  
...  

A household refrigerator is a major energy consumer in all homes. The paper aims to evaluate based, on experimental data, the COP of a 65-liter household refrigerator operating with R600a. The main components and instrumentation of the experimental setup are presented. A mathematical model based on the energy balance of the refrigerated enclosure is developed in order to evaluate the COP. Three experimental data sets have been obtained in quasi-steady-state operating conditions. The results point out that the compressor power absorbed from the grid was 60 [W]. The maximum value for the cooling capacity is 81.73 W while the minimum value is 80.24 W. In terms of COP, the maximum value obtained is 1.362, while the minimum one is 1.337. The COP values obtained in the present study are in good agreement with the ones displayed by the manufacturer in the compressor datasheet. Future development is discussed.


2020 ◽  
pp. 149-152

The energy states for the J , b , ɤ bands and electromagnetic transitions B (E2) values for even – even molybdenum 90 – 94 Mo nuclei are calculated in the present work of "the interacting boson model (IBM-1)" . The parameters of the equation of IBM-1 Hamiltonian are determined which yield the best excellent suit the experimental energy states . The positive parity of energy states are obtained by using IBS1. for program for even 90 – 94 Mo isotopes with bosons number 5 , 4 and 5 respectively. The" reduced transition probability B(E2)" of these neuclei are calculated and compared with the experimental data . The ratio of the excitation energies of the 41+ to 21+ states ( R4/2) are also calculated . The calculated and experimental (R4/2) values showed that the 90 – 94 Mo nuclei have the vibrational dynamical symmetry U(5). Good agreement was found from comparison between the calculated energy states and electric quadruple probabilities B(E2) transition of the 90–94Mo isotopes with the experimental data .


1977 ◽  
Vol 5 (1) ◽  
pp. 6-28 ◽  
Author(s):  
A. L. Browne

Abstract An analytical tool is presented for the prediction of the effects of changes in tread pattern design on thick film wet traction performance. Results are reported for studies in which the analysis, implemented on a digital computer, was used to determine the effect of different tread geometry features, among these being the number, width, and lateral spacing of longitudinal grooves and the angle of zigzags in longitudinal grooves, on thick film wet traction. These results are shown to be in good agreement with experimental data appearing in the literature and are used to formulate guidelines for tread groove network design practice.


2015 ◽  
Vol 11 (3) ◽  
pp. 3224-3228
Author(s):  
Tarek El-Ashram

In this paper we derived a new condition of formation and stability of all crystalline systems and we checked its validity andit is found to be in a good agreement with experimental data. This condition is derived directly from the quantum conditionson the free electron Fermi gas inside the crystal. The new condition relates both the volume of Fermi sphere VF andvolume of Brillouin zone VB by the valence electron concentration VEC as ;𝑽𝑭𝑽𝑩= 𝒏𝑽𝑬𝑪𝟐for all crystalline systems (wheren is the number of atoms per lattice point).


1982 ◽  
Vol 14 (4-5) ◽  
pp. 253-256
Author(s):  
N Sriramula ◽  
M Chaudhuri

An investigation was undertaken on the removal of a model virus, bacterial virus MS2 against Escherichia coli, by sand filtration using untreated, and alum or cationic polyelectrolyte treated media, and uncoagulated as well as alum coagulated influent. Data on discrete virus removal were satisfactorily accounted for by electrokinetic phenomena and diffusion. For virus in association with turbidity, filter coefficients computed from experimental data were in good agreement with those predicted by mechanical straining and gravity settling which were the dominant mechanisms for removal of the turbidity particles to which the viruses attached.


1991 ◽  
Vol 56 (10) ◽  
pp. 2020-2029
Author(s):  
Jindřich Leitner ◽  
Petr Voňka ◽  
Josef Stejskal ◽  
Přemysl Klíma ◽  
Rudolf Hladina

The authors proposed and treated quantitatively a kinetic model for deposition of epitaxial GaAs layers prepared by reaction of trimethylgallium with arsine in hydrogen atmosphere. The transport of gallium to the surface of the substrate is considered as the controlling process. The influence of the rate of chemical reactions in the gas phase and on the substrate surface on the kinetics of the deposition process is neglected. The calculated dependence of the growth rate of the layers on the conditions of the deposition is in a good agreement with experimental data in the temperature range from 600 to 800°C.


Author(s):  
Emre Kahramanoglu ◽  
Silvia Pennino ◽  
Huseyin Yilmaz

The hydrodynamic characteristics of the planing hulls in particular at the planing regime are completely different from the conventional hull forms and the determination of these characteristics is more complicated. In the present study, calm water hydrodynamic characteristics of planing hulls are investigated using a hybrid method. The hybrid method combines the dynamic trim and sinkage from the Zarnick approach with the Savitsky method in order to calculate the total resistance of the planing hull. Since the obtained dynamic trim and sinkage values by using the original Zarnick approach are not in good agreement with experimental data, an improvement is applied to the hybrid method using a reduction function proposed by Garme. The numerical results obtained by the hybrid and improved hybrid method are compared with each other and available experimental data. The results indicate that the improved hybrid method gives better results compared to the hybrid method, especially for the dynamic trim and resistance. Although the results have some discrepancies with experimental data in terms of resistance, trim and sinkage, the improved hybrid method becomes appealing particularly for the preliminary design stage of the planing hulls.


Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2171
Author(s):  
Armin Yousefi ◽  
Ahmad Serjouei ◽  
Reza Hedayati ◽  
Mahdi Bodaghi

In the present study, the fatigue behavior and tensile strength of A6061-T4 aluminum alloy, joined by friction stir spot welding (FSSW), are numerically investigated. The 3D finite element model (FEM) is used to analyze the FSSW joint by means of Abaqus software. The tensile strength is determined for FSSW joints with both a probe hole and a refilled probe hole. In order to calculate the fatigue life of FSSW joints, the hysteresis loop is first determined, and then the plastic strain amplitude is calculated. Finally, by using the Coffin-Manson equation, fatigue life is predicted. The results were verified against available experimental data from other literature, and a good agreement was observed between the FEM results and experimental data. The results showed that the joint’s tensile strength without a probe hole (refilled hole) is higher than the joint with a probe hole. Therefore, re-filling the probe hole is an effective method for structures jointed by FSSW subjected to a static load. The fatigue strength of the joint with a re-filled probe hole was nearly the same as the structure with a probe hole at low applied loads. Additionally, at a high applied load, the fatigue strength of joints with a refilled probe hole was slightly lower than the joint with a probe hole.


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