scholarly journals Simulation and Modeling of Flow in a Gas Compressor

2015 ◽  
Vol 2015 ◽  
pp. 1-7
Author(s):  
Anna Avramenko ◽  
Alexey Frolov ◽  
Jari Hämäläinen
Keyword(s):  
Steady State ◽  
Mass Flow ◽  
Gas Flow ◽  
Simulation Method ◽  
High Mass ◽  
Ansys Fluent ◽  
Flow Rates ◽  
Mass Flow Rates ◽  
Low Mass ◽  
Flow Through

The presented research demonstrates the results of a series of numerical simulations of gas flow through a single-stage centrifugal compressor with a vaneless diffuser. Numerical results were validated with experiments consisting of eight regimes with different mass flow rates. The steady-state and unsteady simulations were done in ANSYS FLUENT 13.0 and NUMECA FINE/TURBO 8.9.1 for one-period geometry due to periodicity of the problem. First-order discretization is insufficient due to strong dissipation effects. Results obtained with second-order discretization agree with the experiments for the steady-state case in the region of high mass flow rates. In the area of low mass flow rates, nonstationary effects significantly influence the flow leading stationary model to poor prediction. Therefore, the unsteady simulations were performed in the region of low mass flow rates. Results of calculation were compared with experimental data. The numerical simulation method in this paper can be used to predict compressor performance.

scholarly journals Experimental and Numerical Investigation the Effect of Grooves Impeller on Rotating Stall of High Speed Blower

2018 ◽  
Vol 8 (04) ◽  
Author(s):  
Muna S. Kassim ◽  
Fouad A. Saleh ◽  
Alaa Th. Aliwi
Keyword(s):  
Numerical Investigation ◽  
Mass Flow ◽  
High Speed ◽  
Static Pressure ◽  
Rotating Stall ◽  
High Mass ◽  
Ansys Fluent ◽  
Flow Rates ◽  
Frontal Wall ◽  
Mass Flow Rates

Experimental and numerical investigation to study the influence of add (one groove and two grooves) to the unshroud impeller onto the rotating stall as well fluctuations of pressure at a high speed blower of centrifugal. Experimental test rig which includes blower of centrifugal, transducer of pressure as well measurement instrumentations are constructed and designed for this study. A data acquisition system (hardware) as well its (software) have been developed into transferring the signal than transducer of pressure to the computer. The experimental work has been implemented through measuring the variation of static pressure as well fluctuation of pressure for two cases of the impeller (with one groove and with two grooves). Static pressure has been taken in different points arranged onto the frontal-wall of a volute casing along one track for two cases of the impeller. This track is angular track about the impeller. The results of experimental show that the fluctuations of pressure for different mass flow rates are nature of non-periodical and the mass flow rates decrease with the fluctuations of pressure increase. Also, the results indicate that the impeller with two grooves show high mass flow rates comparison with the impeller with one groove. Simulation of numerical has been implemented onto blower of centrifugal to analysis both field of flow as well fluctuations of pressure through using ANSYS (FLUENT 15). The simulation of numerical has been carried out through solve the continuity as well momentum equations with the moving reference framework technicality inside a blower. The numerical simulation results show good agreement with the results of experimental.

A Comparative Investigation of Two Types of MHPA Flat-Plate Solar Air Collector Based on Exergy Analysis

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
T. T. Zhu ◽  
Y. H. Diao ◽  
Y. H. Zhao ◽  
C. Ma ◽  
T. Y. Wang ◽  
...  
Keyword(s):  
Flat Plate ◽  
Mass Flow ◽  
Exergy Analysis ◽  
Comparative Investigation ◽  
Exergy Efficiency ◽  
High Mass ◽  
Condenser Section ◽  
Flow Rates ◽  
Mass Flow Rates ◽  
Low Mass

In this study, a comparative investigation of two types of microheat pipe array (MHPA) flat-plate solar air collectors (FPSAC) based on exergy analysis has been conducted. The thermal performance of MHPA-type solar air collectors (SACs) with two different shaped fins is experimentally evaluated. A detailed parametric study is also conducted to examine the effects of various fins, operation parameters, and inlet air temperature at different mass flow rates on thermal and exergy efficiencies. Results indicated that using V-shaped slotted fins at the specified range of mass flow rates can enhance exergy efficiency. Exergy efficiency can be considered as the main criterion to evaluate the performance of MHPA FPSACs. Attaching V-shaped slotted fins on the condenser section of MHPA is more effective than attaching rectangular fins at high mass flow rates. By contrast, the latter is more effective than the former at low mass flow rates.

Application of the Transient Heat Transfer Measurement Technique Using TLC in a Network Configuration With Intersecting Circular Passages

2018 ◽  
Author(s):  
Anika Steurer ◽  
Rico Poser ◽  
Jens von Wolfersdorf ◽  
Stefan Retzko
Keyword(s):  
Heat Transfer ◽  
Steady State ◽  
Mass Flow ◽  
Fluid Temperature ◽  
Thermochromic Liquid Crystal ◽  
Transfer Coefficients ◽  
Flow Rates ◽  
Flow Network ◽  
Mass Flow Rates ◽  
Time Information

The present study deals with the application of the transient thermochromic liquid crystal (TLC) technique in a flow network of intersecting circular passages as a potential internal turbine component cooling geometry. The investigated network consists of six circular passages with a diameter d = 20mm that intersect coplanar at an angle θ = 40°, the innermost in three, the outermost in one intersection level. Two additional non-intersecting passages serve as references. Such a flow network entails specific characteristics associated with the transient TLC method that have to be accounted for in the evaluation process: the strongly curved surfaces, the mixing and mass flow redistribution at each intersection point, and the resulting gradients between the wall and passage centerline temperatures. All this impedes the choice of a representative fluid reference temperature, which results in deviations using established evaluation methods. An alternative evaluation approach is introduced, which is supported by computational results obtained from steady-state three-dimensional RANS simulations using the SST turbulence model. The presented analysis uncouples local heat transfer coefficients from actually measured local temperatures but uses the time information of the thermocouples instead that represents the fluid temperature step change and evolution along the passages. This experimental time information is transferred to the steady-state numerical bulk temperatures, which are finally used as local references to evaluate the transient TLC experiments. As effective local mass flow rates in the passage sections are considered, the approach eventually allows for a conclusion whether heat transfer is locally enhanced due to higher mass flow rates or the intersection effects.

Aerodynamic Performance Evaluation of Axial Flow Fan Using Numerical Techniques

2021 ◽  
Author(s):  
Raghuvaran D. ◽  
Satvik Shenoy ◽  
Srinivas G
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Rotational Speed ◽  
Total Pressure ◽  
Axial Flow ◽  
High Mass ◽  
Ansys Fluent ◽  
Industrial Sectors ◽  
Mass Flow Rates

Abstract Axial flow fans (AFF) are extensively used in various industrial sectors, usually with flows of low resistance and high mass flow rates. The blades, the hub and the shroud are the three major parts of an AFF. Various kinds of optimisation can be implemented to improve the performance of an AFF. The most common type is found to be geometric optimisation including variation in number of blades, modification in hub and shroud radius, change in angle of attack and blade twist, etc. After validation of simulation model and carrying out a grid independence test, parametric analysis was done on an 11-bladed AFF with a shroud of uniform radius using ANSYS Fluent. The rotational speed of the fan and the velocity at fan inlet were the primary variables of the study. The variation in outlet mass flow rate and total pressure was studied for both compressible and incompressible ambient flows. Relation of mass flow rate and total pressure with inlet velocity is observed to be linear and exponential respectively. On the other hand, mass flow rate and total pressure have nearly linear relationship with rotational speed. A comparison of several different axial flow tracks with the baseline case fills one of the research gaps.

EFFERVESCENT ATOMIZATION AT LOW MASS FLOW RATES. PART I: THE INFLUENCE OF SURFACE TENSION

1993 ◽  
Vol 3 (1) ◽  
pp. 77-89 ◽  
Author(s):  
M. T. Lund ◽  
Paul E. Sojka ◽  
Arthur H. Lefebvre ◽  
P. G. Gosselin
Keyword(s):  
Surface Tension ◽  
Mass Flow ◽  
Flow Rates ◽  
Mass Flow Rates ◽  
Low Mass

Experimental and Numerical Investigation of Different Rectangular Volute Geometries for Large Radial Compressors

2011 ◽  
Author(s):  
Michael Bartelt ◽  
Thomas Kwitschinski ◽  
Thomas Ceyrowsky ◽  
Daniel Grates ◽  
Joerg R. Seume
Keyword(s):  
Mass Flow ◽  
Pressure Ratio ◽  
High Mass ◽  
Local Flow ◽  
Flow Rates ◽  
Reduced Dimensions ◽  
External Reference ◽  
Mass Flow Rates ◽  
Compressor Map ◽  
Operating Points

Increases on mass flow rates of modern radial process compressors result on larger machine components. In particular, the dimensions of the outlet volutes increase strongly, resulting in disproportionately large machines whose technical feasibility is restricted due to technological and economical reasons. A resulting aim is to design modern radial compressors much more compact, while improving the efficiency and the pressure ratio. Therefore, the present experimental investigation addresses the compressor behaviour for reduced dimensions of rectangular volutes. Furthermore, the experimental setups are numerically modelled and different operating points are simulated with a commercial CFD-Code. A rectangular, external reference volute is equipped with differently shaped blockage-inlays and the global compressor parameters are measured for all variants. Additionally, the pressure and velocity distributions of the local flow field are determined experimentally for varying mass flow ratios at different circumferentially distributed volute layers. The decrease of the volute cross-section results in a reduction of the compressor map width especially at high mass flow rates. Recommendations are given for designing compact volutes of large radial compressors.

Review of Critical Flowmeters for Gas Flow Measurements

1962 ◽  
Vol 84 (4) ◽  
pp. 447-457 ◽  
Author(s):  
B. T. Arnberg
Keyword(s):  
Mass Flow ◽  
Flow Measurement ◽  
Gas Flow ◽  
Flow Measurements ◽  
Flow Rates ◽  
Real Gas ◽  
Discharge Coefficients ◽  
Critical Nozzles ◽  
Mass Flow Rates ◽  
Flow Functions

Critical flowmeters for accurately measuring the mass flow rates of nonreacting real gases were reviewed. Discussions were presented on theoretical flow functions, on parameters for correlating discharge coefficients, and on the importance of real gas properties. The performance characteristics of critical nozzles and orifices of several designs were reviewed. Approaches were discussed to problems which must be researched before the fullest potential of this type of flow measurement can be realized.

Design and Development of a Radial Turbine for Low Flow Turbocharging

2019 ◽  
Author(s):  
Dhinagaran Ramachandran ◽  
Srinivasa Rao Billa ◽  
Balamurugan Mayandi ◽  
Perumal Balappan ◽  
Shyamaprasad Kanthila ◽  
...  
Keyword(s):  
Transient Response ◽  
Mass Flow ◽  
Aerodynamic Performance ◽  
Low Flow ◽  
Angle Distribution ◽  
Turbine Wheel ◽  
Structural Requirements ◽  
Flow Rates ◽  
Mass Flow Rates ◽  
Low Mass

Abstract The scope of this study is to develop a turbocharger turbine wheel with improved aerodynamic performance at low mass flow rates and with reduced inertia for better transient response. The contrasting effect of geometrical shape and size parameters on the objectives of aerodynamic performance and transient response gives rise to the need to explore the design space for the best design having good trade-off between the multi-objective requirements. The search for an optimum aerodynamic design is a challenge due to structural requirements as well. A turbine wheel that is best suited for the current application is selected from the library as a baseline and this wheel is further optimized to meet the targets. Preliminary screening allowed the identification of parameters having major impact on the objectives and these results have been used to train a Response Surface (RS). Further, in the interest of reducing computational cost, a virtual optimization algorithm based on the RS has been employed to predict optimum design within the design constraints. The optimum designs thus obtained are validated with Computational Fluid Dynamics simulations for flow performance and Finite Element solver for satisfying structural requirements. This approach has allowed for application-based design of turbine wheel for instance, by changing key parameters like blade angle distribution, number of blades, axial length, blade height and width. An inertia reduction up to 10% has been obtained while retaining the performance at low mass flow rates.

Mass flow rate for nearly-free molecular slit flow

1969 ◽  
Vol 35 (3) ◽  
pp. 599-608 ◽  
Author(s):  
J. Daniel Stewart
Keyword(s):  
Mass Flow ◽  
Pressure Ratio ◽  
Molecular Flow ◽  
Two Dimensional ◽  
Flow Rates ◽  
Average Mass ◽  
Slit Flow ◽  
Mass Flow Rates ◽  
Flow Through ◽  
Tank Pressure

The local and average mass flow rates for nearly free molecular flow through a two-dimensional slit are determined for several tank pressure ratios. The equilibrium gas in the two tanks and the container walls are assumed to be at the same temperature and the Willis iterative method with the Bhatnager-Gross-Krook model is used for the analysis. The results for an infinite pressure ratio are also presented in order to illustrate the effects of a finite pressure ratio.

A Comparison of a Mono, Twin and Double Scroll Turbine for Automotive Applications

2015 ◽  
Author(s):  
Jason Walkingshaw ◽  
Georgios Iosifidis ◽  
Tobias Scheuermann ◽  
Dietmar Filsinger ◽  
Nobuyuki Ikeya
Keyword(s):  
Mass Flow ◽  
Flow Characteristics ◽  
High Mass ◽  
Flow Rates ◽  
Engine Simulation ◽  
Engine Model ◽  
Trade Offs ◽  
Mass Flow Rates ◽  
The Individual ◽  
The Impact

As a means of meeting ever increasing emissions and fuel economy demands car manufacturers are using aggressive engine downsizing. To maintain the power output of the engine turbocharging is typically used. Due to the miss-match of the mass flow characteristics of the engine to the turbocharger, at low engine mass flow rates, the turbocharger can suffer from slow response known as “Turbolag”. Mono-scroll turbines are capable of providing good performance at high mass flow rates and in conjunction with low inertia mixed flow turbines can offer some benefits for transient engine response. With a multi-entry system the individual volute sizing can be matched to the single mass flow pulse from the engine cylinders. The exhaust pulse energy can be better utilised by the turbocharger turbine improving turbocharger response, while the interaction of the engine exhaust pulses can be better avoided, improving the scavenging of the engine. The behaviour of a mono-scroll turbocharger with the engine using engine simulation tools has been well established. What requires further investigation is the comparison with multi-entry turbines. CFD (Computational Fluid Dynamics) has been used to examine the single admission behaviour of a twin and double scroll turbine. Turbocharger gas stand maps of the multi-entry turbines have been measured at full and single admission. This data has been used in a 0D engine model. In addition, the turbine stage has been tested on the engine and a validation of the engine model against the engine test data is presented. Using the validated engine model a comparison has been made to understand the differences in the sizing requirements of the turbine and the interaction of the mono-scroll and multi-entry turbines with the engine. The impact of the different efficiency and mass flow rate trends of the mono and multi-entry turbochargers are discussed and the trade-offs between the design configurations regarding on engine behaviour are investigated.

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