The Use of Commercial Software 3D Modeling - Thesis Proposal Example

Final year project interim report Chapter1:Introduction 1 Background information on the project Just like compressors, turbomachines propellers and also shrouded propellers there is usually a small gap(clearance) between the rotor and the casing surrounding them. The key reason for inclusion of this clearance is to avoid rubbing. For compressors, the typical clearance for the rotor is usually about one percent of the rotor’s tip axial chord. Tip clearance flow will occur when the rotor rotates with respect to the end-wall. This flow will finally roll up and forms a tip leakage vortex.Tip leakage has been on study since the 19th century. The studies have involved experimental as well as numerical studies. The outcomes of these studies have shown that tip leakage has huge effects on many performance aspects such asstage efficiency,blade loading, stall and also surge characteristics. With the increasing need for more efficient perfomances, there has been continous studies on this area with the objective of meeting the required performance. The report which is summarized by this interim, will be describing the applications of 3-D commercial Dimensional CFD softwares such as the ANSYS FLUENT to accurately analyse the effects of the rotor tip clearance on a single-stage axial turbine. Investigations will be carried out on various fan stages. The numerical and experimental results that are obtained from these rotor studies shows interaction between rotor tip leakage flows and other characteristics of flow that include secondary flows and stator wakes. According to some researchers, these results from rotortip leakage can be applied to the statorhub leakage flows but the variations in parameters such as velocity across blade span and the centrifugal effects lead to fundamental differences. Therefore, there is a need to do analysis of stator-leakage flows in order to obtain valuable information concerning a section of compressor aerodynamics thatis not clearly understood. Emprical relationships in CFD models is what is used in current industry to quantify loses as a result of leakage. However, in order to attain more meaningful information, they must be confirmed by experimental results. In order to validate various principles behind energy losses due to leakages, this report will entail an experiment. The experiment will be aimed at validating the CFD results. It will involve the use of single-stage axial compressor equipment that will be capable of studying hub leakage flows on cantilevered stators. The design will however require intense knowledge on the field 1.3 Project objectives 1. Analysing the hub leakage flow in a jet engine compressor, turbine stator and rotor bladeusing Numerical(CFD) as well as analytical methods.The relationships between the leakage flow and the different gaps/geometrical arrangements will also be analysed. 2. Comparing the obtained numerical data with simple analytical models. The project will however be numerical based and will include the use of a commercial CFD code. Most of the data processing will be performed by Matlab.This investigation will be on a fan stage with two different tip clearances whose values will be included in the report. Chapter 2:Plan of action 2.1 Work accomplished to date The tasks accomplished to date are research-based. Below is an outline of the occurrences to date. Research on the concepts of tip hub leakage flow and how they affect a turbines performance. This however is necessary for the purpose of understanding the design requirements and specifications. Research on the experimental analysis of the cold-air test.Thisis aimed at comparing experimental data to what will be obtained. Learning of object modelling technique as well as the use of Matlab for purpose of analysing the experiment results. 2.2 Main goals towards completion of the project As of from the week ending 5 of the semester, the following are the main objectives for the project in order. Semester 1: End of week 9: accomplishment of design of the 3D models of the turbine using the solid works software. The models were done to display all the turbines parts, as well as the dimensioning.This will also include simulations using Matlab. Start of week 11:result analysis and validation. This will include comparison of the experimental results with the CFD values. Semester break: 4week duration: continuation of data analysis and analysing for any fault. The analysis entailed collecting of available data on the particular results for comparison. Semester2: End of week 3: performing a more analysis on the results by drawing graphs and graphical models. Start of week 4: Gathering of all the data and making a conclusive compilation of data. The compilation included drawing the various plots. The plots include the plottings obtained from ANSYS simulation results as well as the MATLABplottings. Week 10: Compilation of the final report. The completion of report compilation will be doneafter obtaining the software modelling results. The outlined goals are however illustrated in the Gantt chart as shown in the below figure. 2.3 Proposed Gantt chart Chapter 3: 3.1 Design approach When examining performance of the turbine, the cold-air test is preferred. During the test, there are two possible methods 1. Use of a one- stage core turbine 2. Using a two-stage core turbine A two –stage core turbine is preferred for the high performance and is more efficient. The one- stage however is advantageous for its low cost as well as low maintenance cost. All these however counterbalances. This covers the design of a solid state single-stage turbine. 3.1.1 The design specifications of the fan stage This high pressure ultrasonic single stage axial fan will be made up of a rotor row having blades around it as well as a stator row with diffuser vanes. The main parameters that will be used for the deigned specification are as outlined: Tip diameter Pressure ratio Mass flow rate Hub/tip ratio Design speed Rotor tip speed 3.1.2 Geometry construction Three different CAD models will be developed for the three rotor tip confiqurations of the fan stage. The models will be developed using the solid works design software. One rotor blade as well as one stator vane will be modelled for the purpose of numerical simulation together with periodic boundary conditions. There will also be inclusion of 3d models of the fans. 3.1.3 Grid generation All the three control volumes will be meshed using the Ansys simulation software toolkit. The appropriate functions will be used ehen meshing when determining boundary layers. The control volume will be meshed with tetrahedtral unstructured elements. After the ggriid generation, the grid’s skewness will be determined . A grid generated for a no tip clearance case will also be included for comparison. Appropriate definitions of the boundary conditions such as pressoutlet, pressure inlet periodic etc will done. This same procedure will be used for the other two confiqurations. 3.1.4 CFD analysis a) Numerical algorithm 3-D Navier-stoke stoke equations for steady state condition will be solved the commonly used implicit solver of commercial software (ANSYS FLUENT). b) Boundary conditions The no-slip boundary condition will be identified for the blade, hub as well as the the casing surfaces of both stator and rotor. The next step will be applying of periodic condition to the sunction and the pressure surfaces of the rotor and stator control volumes. Ambient pressure at the inlet will also be specified alongside with the turbulent intesnsity. At the rotors exit, static pressure with the radial equilibrium condition will also be specified. c) Solution methodology Converged solutions for all the three confiqurations at different back pressures will be determined in order to find the pump’s performance over the whole operating range of the fan at various different speeds. Closer to the stall condition, the static exit pressure will be increased in small phases. So as to monitor the convergence, a residual criterion will have to be set. The final step will involve making plots of residuals against number of interactions of the no tip case. 3.1.5 Data validation The CFD data from the ANSYS FLUENT simulations, will be validated using the available data . A comparison of total pressure ratio and the adiabatic efficiency against corrected rate of mass flow will be carried out. The parameters at the casing at different flow conditions are to be determined. These parameters are,mach number plots,and the velocity vector plots. The velocity vector plot will be obtained for both cases of presence and absence of rotor tip clearance. These plots are to be attached to the report document. The following are the plots that will be made as part of data analysis. Match number contour plots for the conditions resulting from the FLUENT and Codings The match number contour plots of near stall condition Chapter 4: 4.1 Literature survey Below is a list of the resources I found useful for the accomplishment of the project research. TANAKA, S. and MURATA, S. (1975).On the Partial Flow Rate Performance of Axial-Flow Compressor and Rotating Stall : 1 st Report, Influences of Hub-Tip Ratio and Stators.Bulletin of JSME, 18(117), pp.256-263. Xiang, J., Schlüter, J. and Duan, F. (2014).CFD Validation and Analysis of a Single-Stage Axial Compressor.AMM, 629, pp.109-118. Koff, B. and Koff, B. (2004). Gas Turbine Technology Evolution: A Designers Perspective. Journal of Propulsion and Power, 20(4), pp.577-595. Reeman, J. and Buswell, R. (1953). An Experimental Single‐stage Air‐cooled Turbine. Aircraft Engineering and Aerospace Technology, 25(8), pp.227-235. Benabed, M. (2012).A numerical investigation of new film cooling hole configuration at the leading edge of asymmetrical turbine blade: part A.Heat Mass Transfer, 49(4), pp.497-508. NASTAC, L. (2012). CFD modeling and simulation in materials processing.Hoboken, N.J., John Wiley & Sons.http://www.123library.org/book_details/?id=62931 CLEMSON UNIVERSITY, UNITED STATES, & NATIONAL ENERGY TECHNOLOGY LABORATORY (U.S.). (1995). Advanced multistage turbine blade aerodynamics, performance, cooling, and heat transfer. Washington, D.C., United States. Dept. of Energy. http://www.osti.gov/servlets/purl/219516-MUGWP2/webviewable/. Chapter 5: Facilities and materials 5.1 Software requirement Most of project’s analyses will be done on MATLAB for windows 7 operating system hoping that it will be compatible for other windows versions. Microsoft word will also be required Microsoft excel. Adobe acrobat would be ideal for the purpose of researching papers which are in pdf format. All these softwares should be compatible with windows 7. For the purpose of accuracy ANCYS software will be necessary for the purpose of simulating the results. 5.2 Hardware requirements A computer with sufficient RAM (2ghz and above) with high processor(2.6ghz or more),Core i3 or above. Hard disk space required should be atleast 1GB. 5.3 References and information sources The sources for this report are placed in categories of journals, books and internet sources. Journals Blade assembly for gas turbine engines.(1974). Composites, 5(6), p.275. Koff, B. and Koff, B. (2004). Gas Turbine Technology Evolution: A Designers Perspective. Journal of Propulsion and Power, 20(4), pp.577-595. Mulac, R. and Adamczyk, J. (1992). The Numerical Simulation of a High-Speed Axial Flow Books ROELKE, R. J., & HAAS, J. E. (1981).Cold-air performance of compressor-drive turbine of Department of Energy upgraded automobile gas turbine engine. Washington, D.C., National Aeronautics and Space Administration, Scientific and Technical Information Branch. ASME TURBO EXPO. (2004). Proceedings of the ASME Turbo Expo 2004: presented at the 2004 ASME Turbo Expo : June 14-17, 2004, Vienna, Austria. New York, N.Y., ASME HANOCA, P, & SHOBHAVATHY, MT. (2011).CFD Analysis to investigate the effect of axial spacing in a single stage transonic axial flow compressor. Hanoca, P and Shobhavathy, MT (2011) CFD Analysis to Investigate the Effect of Axial Spacing in a Single Stage Transonic Axial Flow Compressor. In: Symposium on Applied Aerodynamics and Design of Aerospace Vehicle (SAROD 2011), November 16-18, 2011, Bangalore, India. CMFF03, VAD, J., LAJOS, T., & SCHILLING, R. (2004).Modelling fluid flow: the state of the art. Berlin, Springer RAINS, D. A. (1954).Tip clearance flows in axial compressors and pumps. Pasadena, Cal, California Institute of Technology. NAKASONE, Y., STOLARSKI, T. A., & YOSHIMOTO, S. (2006). Engineering analysis with ANSYS software.Oxford, Butterworth-Heinemann. http://public.eblib.com/choice/publicfullrecord.aspx?p=285842. Internet sources Web.mit.edu, (2014).MIT GTL Past Research. [online] Available at: http://web.mit.edu/aeroastro/labs/gtl/MIT_GTL_past_research.html [Accessed 5 Dec. 2014]. elftpe.nl, (2014).Process & Energy Delft. [online] Available at: http://delftpe.nl/node/146 [Accessed 5 Dec. 2014]. Read More