Sealing of a Shrouded Rotor–Stator System With Preswirl Coolant

1988 ◽  
Vol 110 (2) ◽  
pp. 218-225 ◽  
Author(s):  
Z. B. El-Oun ◽  
P. H. Neller ◽  
A. B. Turner
Keyword(s):  
Pressure Distribution ◽  
Cooling System ◽  
Flow Distribution ◽  
Internal Flow ◽  
Sampling Technique ◽  
Turbine Rotor ◽  
Coolant Flow ◽  
Blade Cooling ◽  
Heated Disk ◽  
Shrouded Rotor

This paper describes an experimental study of a modeled gas turbine rotor–stator system using both preswirled blade coolant and radially outward flowing disk coolant. A double mitered rim seal was used together with, for some tests, an inner seal below the preswirl nozzles and blade feed holes in the rotor which were situated at the same radius. Some flow visualization results are presented together with measurements of pressure distribution, internal flow distribution, and the minimum seal flow necessary to prevent “mainstream” gas ingress into the wheelspace. The experiments are described for a range of rotational speeds up to Reθ = 1.8×106 for various combinations of preswirl flow, disk coolant flow, and “blade” coolant flow. The preswirled coolant flow is shown to have little effect on the pressure distribution below the preswirl nozzles but a gas concentration sampling technique showed that considerable contamination of the preswirled coolant by the frictionally heated disk coolant can occur. A clear pressure inversion effect was observed when coolant was provided by the preswirl nozzles only, whereby the pressure under the rim seal increased with increasing rotational speed. Except for the lowest flow rates, blade coolant flow is shown to increase the sealing flow requirement, but to a very much reduced extent when disk coolant flow is used simultaneously. A nonlinear relationship between minimum sealing flow and Reθ is produced when the blade cooling system is in operation.

scholarly journals Sealing of a Shrouded Rotor-Stator System With Pre-Swirl Coolant

1987 ◽  
Author(s):  
Z. B. El-Oun ◽  
P. H. Neller ◽  
A. B. Turner
Keyword(s):  
Pressure Distribution ◽  
Cooling System ◽  
Flow Distribution ◽  
Internal Flow ◽  
Sampling Technique ◽  
Turbine Rotor ◽  
Swirl Flow ◽  
Coolant Flow ◽  
Heated Disc ◽  
Shrouded Rotor

This paper describes an experimental study of a modelled gas turbine rotor-stator system using both pre-swirled blade coolant and radially outward flowing disc coolant. A double mitred rim seal was used together with, for some tests, an inner seal below the pre-swirl nozzles and blade feed holes in the rotor which were situated at the same radius. Some flow visualization results are presented together with measurements of pressure distribution, internal flow distribution and the minimum seal flow necessary to prevent ‘mainstream’ gas ingress into the wheelspace. The experiments are described for a range of rotational speeds up to Reθ = 1.8 × 106 for various combinations of pre-swirl flow, disc coolant flow and ‘blade’ coolant flow. The pre-swirled coolant flow is shown to have little effect on the pressure distribution below the pre-swirl nozzles but a gas concentration sampling technique showed that considerable contamination of the pre-swirled coolant by the frictionally heated disc coolant can occur. A clear pressure inversion effect was observed when coolant was provided by the pre-swirl nozzles only, whereby the pressure under the rim seal increased with increasing rotational speed. Except for the lowest flow rates, blade coolant flow is shown to increase the sealing flow requirement, but to a very much reduced extent when disc coolant flow is used simultaneously. A non-linear relationship between minimum sealing flow and Reθ is produced when the blade cooling system is in operation.

Numerical Investigation on the Characteristic of the Reverse Flow Phenomenon in a Z-Type Parallel Compact Heat Exchanger With Large Number of Tubes

2018 ◽  
Author(s):  
Jian Zhou ◽  
Ming Ding ◽  
Haozhi Bian ◽  
Yinxing Zhang ◽  
Zhongning Sun
Keyword(s):  
Heat Exchanger ◽  
Pressure Distribution ◽  
Coming Out ◽  
Heat Exchangers ◽  
Cooling System ◽  
Reverse Flow ◽  
Flow Distribution ◽  
Flow Phenomenon ◽  
Compact Heat Exchangers ◽  
Geometry Design

The parallel compact heat exchangers have been widely applied in the various fields such as heat exchangers in chemical engineering, the solar collector, fuel cells and the passive removal heat exchanger in passive containment cooling system (PCCS), etc. The heat exchangers in the PCCS removes out the heat brought by the steam coming out from the broken reactor or primary cooling system. Therefore, the performance of the passive containment cooling system heat exchanger (PCCS HX) will greatly influence the safety and integrity of the containment. In previous investigations on the parallel compact heat exchangers, attentions are focused on the pressure distribution and flow distribution in the heat exchangers. A bad flow distribution in the heat exchanger will reduce the heat performance. More seriously, the coolant in some tubes may boils and the tubes will be overheated, resulting in explosion of tubes. Therefore, the characteristic of pressure distribution and the flow distribution should be investigated for a uniform flow distribution. In the past studies of the compact heat exchangers, the numbers of tube are almost under 72 which is relatively small, while the number of tubes PCCS HX is usually over than 100. And the pressure distribution in compact heat exchangers is assumed that the pressure recovery plays a leading role. However, the more numbers of tube will bring more flow maldistribution, if the geometry design is selected inappropriately. The reverse flow may occur in the heat exchanger, which means that in some tubes, the coolant flows from the tube outlet to the inlet. This phenomenon of reverse flow have never been mentioned in previous studies. The occurrence of the reverse flow will significantly decrease the performance of the heat exchanger and cause a bad influence on the safety of the containment. In the PCCS, the Z-type heat exchanger is one of the choice of PCCS HX (heat exchanger) design. Therefore, the present study focus on the characteristic of reverse flow phenomenon in Z-type heat exchangers. The pressure distribution and the flow distribution have been separately investigated deeply. The conclusion of this study will provide a guide to the geometry design of the PCCS HX with large number of tubes.

Experimental Investigation of Two Competitive High Pressure Turbine Blade Cooling Systems

2017 ◽  
Author(s):  
Sergiy Risnyk ◽  
Andriy Artushenko ◽  
Igor Kravchenko ◽  
Sergii Borys
Keyword(s):  
High Pressure ◽  
Turbine Blade ◽  
Film Cooling ◽  
Cooling System ◽  
Turbine Blades ◽  
Turbine Rotor ◽  
High Pressure Turbine ◽  
Cooling Systems ◽  
Turbine Blade Cooling ◽  
Blade Cooling

Aeroengine high-pressure turbine (HPT) is the key engine component. HPT blade must withstand high inlet temperatures and mechanical loads providing the necessary level of the efficiency. To achieve these objectives effective and complex blade cooling systems (internal convective and film cooling) are used in the HPT design. The objective of this project is to design and investigate the aeroengine HPT blade cooling system that is able to withstand the blade inlet gas temperature level of approx. 1900K but with the minimal cooling airflow amount. HPT blade of the aeroengine with unducted fan (UDF) was taken as a baseline design, namely, the monocrystal blade with a convective multipass system and the film cooling. Advanced HPT blade inter-wall cooling system was designed, investigated and compared with the typical baseline HPT blade. In the advanced HPT blade inter-wall cooling system special types and structure of cooling channels are used. Both types of cooling systems were investigated experimentally in the turbine rotor of the high temperature core engine. Measurements of turbine blades temperatures were performed using crystal temperature sensors (CTS). HPT blades with two competitive cooling systems incorporated with CTS (0,2–0,3 mm size) were installed in the turbine rotor of the core engine and tested on the engine Maximal rate. After tests and the engine disassembly CTSs were extracted and the characteristics of the CTS crystal lattice were transcribed in temperature values. Thermal state of both two competitive cooling systems was validated by experimental data. Numerical and experimental results obtained in the research of HPT blade cooling system are presented in the article. Aeroengine high pressure turbine blade cooling systems designs are described.

Flow in a Simulated Turbine Blade Cooling Channel With Spatially Varying Roughness Caused by Additive Manufacturing Orientation

2020 ◽  
Author(s):  
Stephen T. McClain ◽  
David R. Hanson ◽  
Emily Cinnamon ◽  
Jacob C. Snyder ◽  
Robert F. Kunz ◽  
...  
Keyword(s):  
Turbine Blade ◽  
Inconel 718 ◽  
Rough Surfaces ◽  
Structured Light ◽  
Internal Flow ◽  
Smooth Wall ◽  
Number Range ◽  
Turbine Blade Cooling ◽  
Blade Cooling ◽  
Hot Film

Abstract Because of the effects of gravity acting on the melt region created during the laser sintering process, additively manufactured surfaces that are pointed upward have been shown to exhibit roughness characteristics different from those seen on surfaces that point downward. For this investigation, the Roughness Internal Flow Tunnel (RIFT) and computational fluid dynamics models were used to investigate flow in channels with different roughness on opposing walls of the channel. Three rough surfaces were employed for the investigation. Two of the surfaces were created using scaled, structured-light scans of the upskin and downskin surfaces of an Inconel 718 component which was created at a 45° angle to the printing surface and documented by Snyder et al. [1]. A third rough surface was created for the RIFT investigation using a structured-light scan of a surface similar to the Inconel 718 downskin surface, but a different scaling was used to provide larger roughness elements in the RIFT. The resulting roughness dimensions (Rq/Dh) of the three surfaces used were 0.0064, 0.0156, and 0.0405. The friction coefficients were measured over the range of 10,000 < ReDh < 70,000 for each surface opposed by a smooth wall and opposed by each of the other rough walls. At multiple ReDh values, x-array hot film anemometry was used to characterize the velocity and turbulence profiles for each roughness combination. The friction factor variations for each rough wall opposed by a smooth wall approached complete turbulence. However, when rough surfaces were opposed, the surfaces did not reach complete turbulence over the Reynolds number range investigated. The results of inner variable analysis demonstrate that the roughness function (ΔU+) becomes independent of the roughness condition of the opposing wall providing evidence that Townsend’s Hypothesis holds for the relative roughness values expected for additively manufactured turbine-blade cooling passages.

scholarly journals Flow Simulation And Performance Analysis Of Centrifugal Compressor Using Cfd_Tool

2021 ◽  
Vol 23 (11) ◽  
pp. 693-703
Author(s):  
Tesfaye Barza ◽  
◽  
G. Lakshmikanth ◽  
Keyword(s):  
Performance Analysis ◽  
Pressure Distribution ◽  
Turbulence Model ◽  
Centrifugal Compressor ◽  
Flow Simulation ◽  
Internal Flow ◽  
Design System ◽  
Turbulent Fluid Flow ◽  
Compressor Impeller ◽  
And Performance

This paper is concerned the flow simulation and performance analysis of the Centrifugal Compressor Using CFD – Tool. The complex internal flow of centrifugal compressor can be well analyzed, and the unique design system needs to be developed. It should be early to use the interface and also flexible for input and output. A 3-D flow simulation of turbulent – fluid flow is presented to visualize the flow pattern in-terms of velocity, streamline and pressure distribution on the blade surface are graphically interpreted. The standard K- e turbulence model and the simple model algorithm were chosen for turbulence model and pressure distribution well determined. The simulation was steady Heat transfer and moving reference frame was used to consider the impeller interaction under high resolution. Furthermore, A computational Fluid Dynamics (CFD) 3-D simulation is done to analyze the impeller head and efficiency required of centrifugal compressor. The impeller is rotated for a constant revolution and mass flow rate, in this study initially the geometry of centrifugal compressor impeller is created by an ANSYS Vista CCD, and the Blade modeller done by Bladegen, Finally, CFD analysis was performed in ANSYS CFX using the ANSYS Turbo grid meshing tool. According to the analysis, as the number of impeller blades increases, so does the value of the head and power imparted, as well as the impeller’s efficiency.

Numerical Analysis of Internal Flow Distribution in Scale-Down APR+

2013 ◽  
Vol 37 (9) ◽  
pp. 855-862 ◽  
Author(s):  
Gong Hee Lee ◽  
Young Seok Bang ◽  
Sweng Woong Woo ◽  
Do Hyeong Kim ◽  
Min Gu Kang
Keyword(s):  
Numerical Analysis ◽  
Flow Distribution ◽  
Internal Flow ◽  
Scale Down

scholarly journals The 701F Gas Turbine Design Process: Upgrade and Innovations

1999 ◽  
Author(s):  
B. Facchini ◽  
C. Carcasci ◽  
G. Ferrara ◽  
L. Innocenti ◽  
D. Coutandin ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Design Process ◽  
Cooling System ◽  
Design Procedure ◽  
Operating Conditions ◽  
Pollutant Emission ◽  
Inlet Section ◽  
Blade Cooling ◽  
Cooling Design ◽  
Power Capability

In this paper, a Fiat Avio 701F gas turbine re-design process is presented. This already tested gas turbine has been modified, for a particular re-powering application: a reduction in the net power production is required, whereas efficiency and exhaust temperature have been improved by mean of increased hot gas temperature at the first nozzle inlet section. Consequently this re-powering solution clearly requires consistent re-design efforts to satisfy specific plant operating conditions. The gas turbine power output has been tuned to the required value by reducing the air inlet mass flowrate; the combustion chamber setting has been modified with particular attention to the control of pollutant emission level. The increase of inlet stator turbine temperature necessitated a complete review of the three cooled turbine stages. The aim of greater overall efficiency with inlet and exit turbine temperature increase also involved the introduction of a new blade material. For design tool flexibility the blade cooling design procedure has been improved making better optimization of the cooling system possible. In this paper a detailed description of the several gas turbine modifications with particular attention to the blade cooling design procedure and to the corresponding simulation results is reported. The modifications developed could also be introduced on the new version of the 701F, at full power capability, in order to get better efficiency and power.

A Highly Efficient Integrated Silicon-Microchannel Cooler for Multi-Module Electronic Microsystems-Model Design, Optimization and Performance Validation

2020 ◽  
pp. 1-38
Author(s):  
Jiejun Wang ◽  
Tao Wang ◽  
Qiuyan Li ◽  
Yiming Li ◽  
Chuangui Wu ◽  
...  
Keyword(s):  
Heat Flux ◽  
Flow Distribution ◽  
Development Trend ◽  
High Heat ◽  
Coolant Flow ◽  
Maximum Temperature ◽  
High Heat Flux ◽  
Highly Efficient ◽  
And Performance ◽  
Performance Validation

Abstract Recently, the development trend of multi-module and multi-function in electronic microsystems makes the ever-increasing heat flux problem more serious. In this study, a highly efficient integrated single-phase microchannel cooler with four heat sources is presented for handling the challenges from both working independently of all electronic modules and the high heat flux. Numerical and experimental study are both conducted. By optimizing the structural design and the fabricated process, the presented microchannel cooler has outstanding cooling performance, which contains desired fluid flow distribution, pressure drop, heat transfer and combination thereof. Results reveals uniform coolant flow dissipates four individual heaters independently, and their maximal temperature difference below 4 °C. Beyond this, high heat flux removal (707.6 W/cm2) is realized with extremely low coolant flow rate (45 ml/min), and the maximum temperature rise is less than 60 °C. This study provides a referable solution for the thermal management of multi-module heat source and high heat flux in compact electronic microsystems.

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