Fabrication and Experimental Investigation of a Novel 3D Hydrodynamic Focusing Micro Cytometric Device

2014 ◽  
Vol 526 ◽  
pp. 242-249
Author(s):  
Yong Quan Wang ◽  
Jing Yuan Wang ◽  
Hua Ling Chen
Keyword(s):  
Experimental Investigation ◽  
Soft Lithography ◽  
Operating Conditions ◽  
Experimental Results ◽  
Experimental Investigations ◽  
Hydrodynamic Focusing ◽  
Channel Depth ◽  
Feature Parameter ◽  
Micro Molding ◽  
Pdms Device

This paper presents the fabrication of a novel micro-machined cytometric device, and the experimental investigations for its 3D hydrodynamic focusing performance. The proposed device is simple in structure, with the uniqueness that the depth of its microchannels is non-uniform. Using the SU-8 soft lithography containing two exposures, as well as micro-molding techniques, the PDMS device is successfully fabricated. Two kinds of experiments, i.e., the red ink fluidity observation experiments and the fluorescent optical experiments, are then performed for the device prototypes with different step heights, or channel depth differences, to explore the influence laws of the feature parameter on the devices hydrodynamic focusing behaviors. The experimental results show that the introducing of the steps can efficiently enhance the vertical focusing performance of the device. At appropriate geometry and operating conditions, good 3D hydrodynamic focusing can be obtained.

Experimental Investigations of Pressure Drop in the Combustion Chamber of Gas Turbine

1989 ◽  
Author(s):  
Marek Dzida ◽  
Krzysztof Kosowski
Keyword(s):  
Pressure Drop ◽  
Combustion Chamber ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Operating Conditions ◽  
Experimental Results ◽  
Experimental Investigations ◽  
Relative Pressure ◽  
Wide Range ◽  
Few Data

In bibliography we can find many methods of determining pressure drop in the combustion chambers of gas turbines, but there is only very few data of experimental results. This article presents the experimental investigations of pressure drop in the combustion chamber over a wide range of part-load performances (from minimal power up to take-off power). Our research was carried out on an aircraft gas turbine of small output. The experimental results have proved that relative pressure drop changes with respect to fuel flow over the whole range of operating conditions. The results were then compared with theoretical methods.

Experimental Investigation of De-Oiling Hydrocyclone

2013 ◽  
Vol 545 ◽  
pp. 230-235
Author(s):  
Wongsarivej Pratarn ◽  
Srirahong Kanawut ◽  
Sawasdisevi Thanit
Keyword(s):  
Experimental Investigation ◽  
Oil Recovery ◽  
Separation Efficiency ◽  
Operating Conditions ◽  
Experimental Results ◽  
Flow Ratio ◽  
Inlet Velocity

Even though the hydrocyclone can be well used for de-oiling, the major problem with normal hydrocyclones is that they discharge relatively large amounts of oil with the water through the underflow. Therefore, the suitable hydrocyclone proportion and optimum hydrocyclone operating conditions should be investigated carefully to achieve better separation efficiency. In this research, a 35 mm hydrocyclone was studied for separating 25% of oil and 75% of water. The objective of the present manuscript was to investigate the important parameter and operating conditions that affected the oil recovery in the overflow. The investigated factors were inlet diameter, inlet velocity and flow ratio. From the experimental results obtained it could be concluded that 1) a decrease in inlet diameter led to an increase in the oil recovery in the overflow; 2) an increase in inlet velocity led to an increase in the oil recovery in overflow. In fact, the inlet velocity that provided the best oil recovery in this research was 8 m/s; 3) an increase in the flow ratio led to an increase in the oil recovery in the overflow.

An Experimental Investigation of Coupled van der Pol Oscillators

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
Bhaskar Choubey
Keyword(s):  
Experimental Investigation ◽  
Chaotic Behavior ◽  
Experimental Results ◽  
Experimental Investigations ◽  
Van Der Pol ◽  
Chaotic Region ◽  
Van Der Pol Oscillators ◽  
Electronic Oscillators

Experimental investigations of synchronization of linearly diffusive coupled van der Pol electronic oscillators are reported. In addition to in- and antiphase stable oscillations, shifted symmetric and asymmetric trajectories have been observed experimentally. However, the experiments have failed to produce stable chaotic behavior in these systems. Extended numeric simulations are then performed to show that the previously believed chaotic region is a transient numeric effect, thereby validating experimental results.

Journal Bearing Lubrication and Design

1948 ◽  
Vol 158 (1) ◽  
pp. 250-254
Author(s):  
A. S. T. Thomson
Keyword(s):  
Experimental Investigation ◽  
Applied Load ◽  
Journal Bearing ◽  
Point Contact ◽  
Journal Bearings ◽  
Operating Conditions ◽  
Experimental Results ◽  
Radial Clearance ◽  
Series Of Experiments ◽  
Loaded Side

The paper summarizes the results of an experimental investigation on the effects of variation in bearing width and radial clearance on the operating conditions of centrally loaded clearance journal bearings, the bearing arc being kept constant at 120 deg. The investigation, which was carried out prior to 1940, is complementary to an earlier paper by the author in which the effects of variations in bearing width and arc of embrace were investigated. The experimental results are compared with theoretical values modified by the relevant leakage coefficients. The measure of agreement obtained indicates that theoretical values so modified may be used with confidence in design. A short series of experiments is described; in these, high-point contact at starting and stopping is eliminated by supplying oil to a groove in the loaded side of the bearing at a pressure sufficiently great to overcome the applied load. The effect of a groove on the loaded side of the brass under various conditions of lubrication is investigated.

scholarly journals Experimental investigation of friction behavior in pre-sliding regime for pneumatic cylinder

2014 ◽  
Vol 36 (4) ◽  
pp. 283-290
Author(s):  
Tran Xuan Bo ◽  
Pham Tat Thang ◽  
Do Thanh Cong ◽  
Ngo Sy Loc
Keyword(s):  
Friction Force ◽  
Friction Model ◽  
Operating Conditions ◽  
Experimental Results ◽  
Hysteretic Behavior ◽  
Pneumatic Cylinder ◽  
Experimental Investigations ◽  
Friction Behavior ◽  
Piston Displacement ◽  
Pneumatic Cylinders

Friction always presents in pneumatic cylinders and causes difficulties in controlling position and velocity of pneumatic systems. In order to improve the control performance of the pneumatic systems, it is necessary to fully understand behavior of friction in the pneumatic cylinders. So far, dynamic friction behavior of pneumatic cylinders has been investigated but mainly focused on the friction behavior in sliding regime. In pre-sliding regime, friction behavior has not been investigated. In this paper, experimental investigations of friction behavior of a pneumatic cylinder in pre-sliding regime are made. The friction force is calculated from the equation of motion of the piston using the measured values of pressures in the two cylinder chambers and the piston displacement. The pressures are controlled by using two proportional pressure control valve. The friction force versus piston displacement characteristics are measured and analysed under various operating conditions of the applied force and the pressures. Experimental results show that: i) the piston motion in pre-sliding regime exhibits a nonlinear spring behavior; ii) hysteretic behavior with nonlocal memory is verified; iii) the pressures have influence only on the size of the hysteretic loop. These experimental results can be applied to develop a friction model for pneumatic cylinders.

Numerical simulation and experimental performance research of cylindrical vane pump

2021 ◽  
pp. 095440622110200
Author(s):  
Yiqi Cheng ◽  
Xinhua Wang ◽  
Waheed Ur Rehman ◽  
Tao Sun ◽  
Hasan Shahzad ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Rotational Velocity ◽  
Geometric Theory ◽  
Mechanical Efficiency ◽  
Operating Conditions ◽  
Experimental Results ◽  
Field Analysis ◽  
Total Efficiency ◽  
Three Dimensional Model ◽  
Vane Pump

This study presents a novel cylindrical vane pump based on the traditional working principle. The efficiency of the cylindrical vane pump was verified by experimental validation and numerical analysis. Numerical analysis, such as kinematics analysis, was performed in Pro/Mechanism and unsteady flow-field analysis was performed using ANSYS FLUENT. The stator surface equations were derived using the geometric theory of the applied spatial triangulation function. A three-dimensional model of the cylindrical vane pump was established with the help of MATLAB and Pro/E. The kinematic analysis helped in developing kinematic equations for cylindrical vane pumps and proved the effectiveness of the structural design. The maximum inaccuracy error of the computational fluid dynamics (CFD) model was 5.7% compared with the experimental results, and the CFD results show that the structure of the pump was reasonable. An experimental test bench was developed, and the results were in excellent agreement with the numerical results of CFD. The experimental results show that the cylindrical vane pump satisfied the three-element design of a positive-displacement pump and the trend of changes in efficiency was the same for all types of efficiency under different operating conditions. Furthermore, the volumetric efficiency presented a nonlinear positive correlation with increased rotational velocity, the mechanical efficiency showed a nonlinear negative correlation, and the total efficiency first increased and then decreased. When the rotational velocity was 1.33[Formula: see text] and the discharge pressure was 0.68[Formula: see text], the total efficiency reached its maximum value.

Experimental investigations to predict optimistic biodiesel(s) and its optimistic operating conditions by varying ignition delay period and fuel spray pressures for lower emissions and better performance

2020 ◽  
Vol 234 (19) ◽  
pp. 3890-3902
Author(s):  
Vishal V Patil ◽  
Ranjit S Patil
Keyword(s):  
Methyl Ester ◽  
Ignition Delay ◽  
Seed Oil ◽  
Delay Period ◽  
Operating Conditions ◽  
Experimental Investigations ◽  
Rubber Seed Oil ◽  
Rubber Seed ◽  
Neem Seed Oil ◽  
Ignition Delay Period

In this study, different characteristics of sustainable renewable biodiesels (those have a high potential of their production worldwide and in India) were compared with the characteristics of neat diesel to determine optimistic biodiesel for the diesel engine at 250 bar spray pressure. Optimistic fuel gives a comparatively lower level of emissions and better performance than other selected fuels in the study. Rubber seed oil methyl ester was investigated as an optimistic fuel among the other selected fuels such as sunflower oil methyl ester, neem seed oil methyl ester, and neat diesel. To enhance the performance characteristics and to further decrease the level of emission characteristics of fuel ROME, further experiments were conducted at higher spray (injection) pressures of 500 bar, 625 bar, and 750 bar with varying ignition delay period via varying its spray timings such as 8°, 13°, 18°, 23°, 28°, and 33° before top dead center. Spray pressure 250 bar at 23° before top dead center was investigated as an optimistic operating condition where fuel rubber seed oil methyl ester gives negligible hydrocarbon emissions (0.019 g/kW h) while its nitrogen oxide (NOX) emissions were about 70% lesser than those observed with neat diesel, respectively.

Experimental Investigation on the Rubbing Process of Labyrinth Seals Considering the Material Combination

2020 ◽  
Author(s):  
Lisa Hühn ◽  
Oliver Munz ◽  
Corina Schwitzke ◽  
Hans-Jörg Bauer
Keyword(s):  
Turbine Blades ◽  
Design Guidelines ◽  
Operating Conditions ◽  
Contact Forces ◽  
Experimental Investigations ◽  
Process Data ◽  
Labyrinth Seals ◽  
Material Combination ◽  
Higher Temperature ◽  
And Control

Abstract Labyrinth seals are used to prevent and control the mass flow rate between rotating components. Due to thermally and mechanically induced expansions during operation and transient flight maneuvers, a contact, the so-called rubbing process, between rotor and stator cannot be excluded. A large amount of rubbing process data concerning numerical and experimental investigations is available in public literature as well as at the Institute of Thermal Turbomachinery (ITS). The investigations were carried out for different operating conditions, material combinations, and component geometries. In combination with the experiments presented in this paper, the effects of the different variables on load due to rubbing are compared, and discussed with the focus lying on the material combination. The influence of the material on the loads can be identified as detailed as never before. For example, the contact forces in the current experiments are higher due to a higher temperature resistance of Young’s modulus. The analysis will also be based on the rubbing of turbine blades. Design guidelines are derived for labyrinth seals with improved properties regarding tolerance of rub events. Based on the knowledge obtained, guidelines for designing reliable labyrinth seals for future engines are discussed.

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