A Comparison of the Measured and Predicted Flow Field in a Modern Fan-Bypass Configuration

1993 ◽  
Vol 115 (2) ◽  
pp. 273-282 ◽  
Author(s):  
R. K. Goyal ◽  
W. N. Dawes
Keyword(s):  
Experimental Data ◽  
Stokes Flow ◽  
Radial Flow ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Single Stage ◽  
Navier Stokes ◽  
Three Dimensional Flow ◽  
Flow Solver ◽  
Bypass Ratio

A three-dimensional viscous Navier–Stokes flow solver was used to predict core and bypass rotor performance and radial flow characteristics of a 4.6:1 bypass ratio, single-stage fan. The three-dimensional flow solver can handle several blade rows simultaneously and has the capability to include a downstream splitter. Results of the analysis are compared with experimental data obtained during rig testing of a modern high bypass single-stage turbofan in which rotor performance for both bypass and core streams was measured.

A Comparison of the Measured and Predicted Flowfield in a Modern Fan-Bypass Configuration

1992 ◽  
Author(s):  
R. K. Goyal ◽  
W. N. Dawes
Keyword(s):  
Experimental Data ◽  
Stokes Flow ◽  
Radial Flow ◽  
Flow Characteristics ◽  
Single Stage ◽  
Navier Stokes ◽  
Flow Solver ◽  
Bypass Ratio

A 3-D viscous Navier-Stokes flow solver was used to predict core and bypass rotor performance and radial flow characteristics of a 4.6:1 bypass ratio, single stage fan. The 3-D flow solver can handle several blade rows simultaneously and has the capability to include a downstream splitter. Results of the analysis are compared with experimental data obtained during rig testing of a modern high bypass single stage turbofan in which rotor performance for both bypass and core streams was measured.

Effects of Tip Clearance on Hot Streak Migration in a High-Subsonic Single-Stage Turbine

2000 ◽  
Author(s):  
Daniel J. Dorney ◽  
Douglas L. Sondak
Keyword(s):  
Experimental Data ◽  
Three Dimensional ◽  
Single Stage ◽  
Rotor Blades ◽  
Tip Clearance ◽  
Navier Stokes ◽  
Radial Spreading ◽  
Rotor Surface ◽  
Hot Streak ◽  
Turbine Airfoils

Experimental data have shown that combustor temperature non-uniformities can lead to the excessive heating of first-stage rotor blades in turbines. This heating of the rotor blades can lead to thermal fatigue and degrade turbine performance. The results of recent studies have shown that variations in the circumferential location, or clocking, of the first-stage vane airfoils can be used to minimize the adverse effects of the hot streaks due to the hot fluid mixing with the cooler fluid contained in the vane wake. In addition, the effects of the hot streak/airfoil count ratio on the heating patterns of turbine airfoils have been quantified. In the present investigation, three-dimensional unsteady Navier-Stokes simulations have been performed for a single-stage high-pressure turbine geometry operating in high subsonic flow to study the effects of tip clearance on hot streak migration. Baseline simulations were initially performed without hot streaks to compare with the experimental data. Two simulations were then performed with a superimposed combustor hot streak; in the first the tip clearance was set at the experimental value, while in the second the rotor was allowed to scrape along the outer case (i.e., the limit as the tip clearance goes to zero). The predicted results for the baseline simulations show good agreement with the available experimental data. The simulations with the hot streak indicate that the tip clearance increases the radial spreading of the hot fluid, and increases the integrated rotor surface temperature compared to the case without tip clearance.

scholarly journals Feasible Concept of an Air-Driven Fan with a Tip Turbine for a High-Bypass Propulsion System

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3350 ◽  
Author(s):  
Guoping Huang ◽  
Xin Xiang ◽  
Chen Xia ◽  
Weiyu Lu ◽  
Lei Li
Keyword(s):  
Fluid Dynamics ◽  
Carbon Dioxide Emissions ◽  
Three Dimensional ◽  
Propulsion System ◽  
Navier Stokes ◽  
Three Dimensional Flow ◽  
Low Pressure Turbine ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method ◽  
Bypass Ratio

The reduction in specific fuel consumption (SFC) is crucial for small/mid-size cost-controllable aircraft, which is very conducive to reducing cost and carbon dioxide emissions. To decrease the SFC, increasing the bypass ratio (BPR) is an important way. Conventional high-BPR engines have several limitations, especially the conflicting spool-speed requirements of a fan and a low-pressure turbine. This research proposes an air-driven fan with a tip turbine (ADFTT) as a potential device for a high-bypass propulsion system. Moreover, a possible application of this ADFTT is introduced. Thermodynamic analysis results show that an ADFTT can improve thrust from a prototype turbofan. As a demonstration, we selected a typical small-thrust turbofan as the prototype and applied the ADFTT concept to improve this model. Three-dimensional flow fields were numerically simulated through a Reynolds averaged Navier-Stokes (RANS)-based computational fluid dynamics (CFD) method. The performance of this ADFTT has the possibility of amplifying the BPR more than four times and increasing the thrust by approximately 84% in comparison with the prototype turbofan.

scholarly journals Effects of Hot Streak Shape on Rotor Heating in a High-Subsonic Single-Stage Turbine

2000 ◽  
Author(s):  
Daniel J. Dorney ◽  
Karen L. Gundy-Burlet
Keyword(s):  
Experimental Data ◽  
Surface Area ◽  
Three Dimensional ◽  
Secondary Flows ◽  
Single Stage ◽  
Rotor Blades ◽  
Navier Stokes ◽  
Strong Function ◽  
Hot Streak ◽  
Turbine Airfoils

Experimental data have shown that combustor temperature non-uniformities can lead to the excessive heating of first-stage rotor blades in turbines. This heating of the rotor blades can lead to thermal fatigue and degrade turbine performance. The results of recent studies have shown that variations in the circumferential location (clocking) of the hot streak relative to the first-stage vane airfoils can be used to minimize the adverse effects of the hot streak. The effects of the hot streak/airfoil count ratio on the heating patterns of turbine airfoils have also been evaluated. In the present investigation, three-dimensional unsteady Navier-Stokes simulations have been performed for a single-stage high-pressure turbine operating in high subsonic flow. In addition to a simulation of the baseline turbine, simulations have been performed for circular and elliptical hot streaks of varying sizes in an effort to represent different combustor designs. The predicted results for the baseline simulation show good agreement with the available experimental data. The results of the hot streak simulations indicate: that a) elliptical hot streaks mix more rapidly than circular hot streaks, b) for small hot streak surface area the average rotor temperature is not a strong function of hot streak temperature ratio or shape, and c) hot streaks with larger surface area interact with the secondary flows at the rotor hub endwall, generating an additional high temperature region.

Investigation of the Tonal Acoustic Field of a Transonic Fanstage by Time-Domain CFD-Calculations With Arbitrary Blade Counts

2004 ◽  
Author(s):  
Rainer Schnell
Keyword(s):  
Experimental Data ◽  
Boundary Conditions ◽  
Acoustic Field ◽  
Time Domain ◽  
Near Field ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Flow Data ◽  
Tonal Noise ◽  
Flow Solver

In order to investigate the tonal noise generated by viscous blade/vane interaction in a typical transonic bypass engine fan stage, time domain calculations were carried out with the non-linear Navier-Stokes solver TRACE. The propagating acoustic field was obtained by a modal decomposition of near field flow data. Comparisons with available experimental data in the bypass duct casing are presented. Different OGV designs of the investigated fanstage were evaluated with respect to the emitted tonal noise of the stage. To ensure the correct modal structure of the acoustic field it is vital to employ the correct blade count ratio in numerical simulations. To accomplish this efficiently, phase-lagged boundary conditions were incorporated into the employed flow solver. The method has been validated using a counter-rotating propfan configuration and was then applied for the three dimensional, spatially highly resolved fanstage calculation.

Effects of Tip Clearance on Hot Streak Migration in a High-Subsonic Single-Stage Turbine

2000 ◽  
Vol 122 (4) ◽  
pp. 613-620 ◽  
Author(s):  
Daniel J. Dorney ◽  
Douglas L. Sondak
Keyword(s):  
Experimental Data ◽  
Three Dimensional ◽  
Single Stage ◽  
Rotor Blades ◽  
Tip Clearance ◽  
Navier Stokes ◽  
Radial Spreading ◽  
Rotor Surface ◽  
Hot Streak ◽  
Turbine Airfoils

Experimental data have shown that combustor temperature nonuniformities can lead to the excessive heating of first-stage rotor blades in turbines. This heating of the rotor blades can lead to thermal fatigue and degrade turbine performance. The results of recent studies have shown that variations in the circumferential location, or clocking, of the first-stage vane airfoils can be used to minimize the adverse effects of the hot streaks due to the hot fluid mixing with the cooler fluid contained in the vane wake. In addition, the effects of the hot streak/airfoil count ratio on the heating patterns of turbine airfoils have been quantified. In the present investigation, three-dimensional unsteady Navier–Stokes simulations have been performed for a single-stage high-pressure turbine geometry operating in high subsonic flow to study the effects of tip clearance on hot streak migration. Baseline simulations were initially performed without hot streaks to compare with the experimental data. Two simulations were then performed with a superimposed combustor hot streak; in the first the tip clearance was set at the experimental value, while in the second the rotor was allowed to scrape along the outer case (i.e., the limit as the tip clearance goes to zero). The predicted results for the baseline simulations show good agreement with the available experimental data. The simulations with the hot streak indicate that the tip clearance increases the radial spreading of the hot fluid, and increases the integrated rotor surface temperature compared to the case without tip clearance. [S0889-504X(00)02204-2]

Shape Optimization of High-Speed Axial Compressor Blades Using 3D Navier-Stokes Flow Physics

2001 ◽  
Author(s):  
June Chung ◽  
Jeonghwan Shim ◽  
Ki D. Lee
Keyword(s):  
Stokes Flow ◽  
Design Method ◽  
Three Dimensional ◽  
Axial Compressor ◽  
Navier Stokes ◽  
Three Dimensional Flow ◽  
Compressor Blades ◽  
Flow Physics ◽  
Dimensional Flow ◽  
Blade Section

A CFD-based design method for transonic axial compressor blades was developed based on three-dimensional Navier-Stokes flow physics. The method starts with a three-dimensional flow analysis of an initial blade, followed by the sectional design optimization performed on a grid plane at a span station with spanwise flux components held fixed. This approach allows the sectional design to include the three-dimensional effects in compressor flows and thus overcome the difficulties associated with the use of quasi-three-dimensional flow physics in sectional designs. The “sectional three-dimensional” analysis at a span station, regardless of the initial flow condition, produced a flow solution nearly identical to the three-dimensional flow solution at the span station. After the validation of the sectional three-dimensional analysis, the developed design method was successfully applied to multiple span stations of NASA Rotor 37 blade in the inverse mode of finding a target geometry corresponding to a specified target pressure distribution. The method was also applied to optimize the adiabatic efficiencies of the blade section of Rotor 37 at 70 percent span station. The design results from two design attempts with different initial geometry indicate that there is not a lot of room for improvement for the blade section of Rotor 37 at 70 percent span station, but the present design method is capable of producing a large performance gain for a blade with lower efficiency.

A three-dimensional incompressible Navier-Stokes flow solver using primitive variables

AIAA Journal ◽  
1986 ◽  
Vol 24 (3) ◽  
pp. 390-396 ◽  
Author(s):  
Dochan Kwak ◽  
James L. C. Chang ◽  
Samuel P. Shanks ◽  
Sukumar R. Chakravarthy
Keyword(s):  
Stokes Flow ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Flow Solver ◽  
Primitive Variables
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