scholarly journals CHARACTERISTICS OF HEAT TRANSFER IN FIRE TUBE OF MARINE GAS TURBINE ENGINE IN STARTING MODE

2018 ◽  
pp. 66-74
Author(s):  
Yuri Gorjanovich Volodin ◽  
Yury Ivanovich Matveev ◽  
Mikhail Yurievich Khramov
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Heat Flow ◽  
Turbulent Boundary Layer ◽  
Gas Turbine ◽  
Gas Flow ◽  
Experimental Studies ◽  
Gas Turbine Engine ◽  
Working Fluid ◽  
Turbine Engine

The paper presents the results of experimental studies of heat transfer in a cylindrical tube, which is a simulation model of a fire tube. The experiments were performed on a gas-dynamic pipe of open type. The starting mode during operation of the gas turbine engine is one of the main modes in which failures sometimes occur. The failure may occur due to external heat transfer mode, when the thermal parameters of the gas flow exceed the calculated values and there takes place intense local heating of the streamlined surface of the structural element(s) of the engine. Experimental studies were carried out at different intensity of the increasing temperature of the working fluid, which allowed to fix the phenomenon of laminarization of the thermal turbulent boundary layer at the heat flow directed from the gas flow to the channel wall. In the event of laminarization phenomenon, the values of local heat transfer coefficients are reduced by 2.5-3 times. Since the discovery of this phenomenon, it has also been observed in various situations of accelerating the gas flow and even at high degrees of heating of the cylindrical pipe wall under stationary flow conditions. This phenomenon has been recorded for the first time in the non-stationary mode and the specified direction of the heat flow. The temperature head or temperature factor is proposed as a laminarization parameter of a turbulent boundary layer, and the boundary of the laminarization area of a turbulent boundary layer is Δ T ≥ 700 K.

Study on Accuracy of Heat Transfer Coefficient Determination in the Bearing Chamber for Gas Turbine Engine

2020 ◽  
Author(s):  
Illia Petukhov ◽  
Taras Mykhailenko ◽  
Sergiy Yepifanov ◽  
Oleg Shevchuk
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Gas Turbine ◽  
Experimental Studies ◽  
Gas Turbine Engine ◽  
Operating Conditions ◽  
Turbine Engine ◽  
Cooling Medium ◽  
External Cooling

Abstract The heat transfer coefficient (HTC) is one of the key parameters that should be known at the stage of the bearing chamber design. This ensures safe temperature conditions for the lubrication oil and reliable operation of the gas turbine engine. The temperature gradient method is commonly used in experimental practice to determinate the HTC. The accuracy of the HTC determination is sensitive to changing of the bearing chamber operating conditions and should be analyzed at the stage of experimental studies planning. This paper presents a study on the accuracy of HTC determination when the external cooling of the bearing chamber is used to obtain the temperature difference sufficient for measurement. Three ways to reduce the relative error of the HTC determination in the bearing chamber were analyzed: i) decreasing the temperature measurement error; ii) decreasing the temperature of external cooling medium; iii) increasing the external heat transfer coefficient and contribution of wall thermal resistance optimization. For different operating conditions of the bearing chamber, the temperature of the outer wall that ensures the specified accuracy of the experimental HTC and the required parameters of the cooling medium were determined and recommended for practical implementation.

Investigation of Aerodynamics and Heat Transfer of a Highly Loaded Turbine Blade Using the Universal Intermittency Function

2017 ◽  
Author(s):  
A. Nikparto ◽  
M. T. Schobeiri
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Reynolds Number ◽  
Gas Turbine ◽  
Flow Condition ◽  
Computational Results ◽  
Turbine Engine ◽  
Low Pressure Turbine ◽  
Unsteady Flow Condition ◽  
Highly Loaded

Efficiency and performance of gas turbine engines are affected by the flow field around the blades. The flow field inside a gas turbine engine is very complex. One of the characteristics of the flow inside an engine is existence of periodic unsteady wakes, originating from the upstream stator blades. The unsteady wakes, with their highly vortical core, impinge on the downstream blade surfaces and cause an intermittent transition of the flow regime from laminar to turbulent. This study aims at investigating and modeling the behavior and development of the boundary layer along the suction surface of a highly loaded low-pressure turbine blade under steady and unsteady inlet flow condition. The current paper includes results of a computational work substantiated by the experimental verifications. For the experimental investigations, the linear cascade facility in Turbomachinery Performance and Flow research Lab (TPFL) at Texas A&M University was used to simulate the periodic unsteady flow condition inside gas turbine engine. Moving wakes, originating from upstream blades, were simulated in this facility by moving rods attached to two parallel timing belts. Measurements and calculations were conducted at Reynolds number of 110,000. This Reynolds number pertains to cruise condition of a low-pressure turbine. At this Reynolds number, the flow around the blades is transitional and highly susceptible to flow separation. Aerodynamics experiments include measuring the boundary layer, locating its transition, separation and finally re-attachment using miniature hot wire probes. Heat transfer measurements along the suction and pressure surfaces were conducted utilizing a specially designed heat transfer blade that was instrumented with liquid crystal coating. To numerically simulate the transitional behavior of the boundary layer under periodic unsteady flow condition, a new intermittency function is developed which is based on the universal intermittency function developed by Chakka and Schobeiri [1]. Accurate prediction of the boundary layer behavior under the above conditions requires minimum and the maximum intermittency functions. These functions were developed inductively using the experimental results that were obtained in the absence of flow separation. In the current investigation the impact of the separation on the minimum and maximum intermittency are accounted for. The enhanced minimum and maximum intermittency functions along with the universal intermittency are implemented in a RANS based solver for computational simulation. The computational results are compared with (a) experimental ones and (b) with the computational results from RANS that involves Langtry-Menter [2, 3] method.

The Effect of Heat Transfer Coefficient Increase on Tip Clearance Control in H.P. Compressors in Gas Turbine Engine

2013 ◽  
Author(s):  
Godwin Ita Ekong ◽  
Christopher A. Long ◽  
Peter R. N. Childs
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Gas Turbine ◽  
Time Constant ◽  
Gas Turbine Engine ◽  
Operating Conditions ◽  
Tip Clearance ◽  
Test Facility ◽  
Turbine Engine

Compressor tip clearance for a gas turbine engine application is the radial gap between the stationary compressor casing and the rotating blades. The gap varies significantly during different operating conditions of the engine due to centrifugal forces on the rotor and differential thermal expansions in the discs and casing. The tip clearance in the axial flow compressor of modern commercial civil aero-engines is of significance in terms of both mechanical integrity and performance. In general, the clearance is of critical importance to civil airline operators and their customers alike because as the clearance between the compressor blade tips and the casing increases, the aerodynamic efficiency will decrease and therefore the specific fuel consumption and operating costs will increase. This paper reports on the development of a range of concepts and their evaluation for the reduction and control of tip clearance in H.P. compressors using an enhanced heat transfer coefficient approach. This would lead to improvement in cruise tip clearances. A test facility has been developed for the study at the University of Sussex, incorporating a rotor and an inner shaft scaled down from a Rolls-Royce Trent aero-engine to a ratio of 0.7:1 with a rotational speed of up to 10000 rpm. The idle and maximum take-off conditions in the square cycle correspond to in-cavity rotational Reynolds numbers of 3.1×106 ≤ Reφ ≤ 1.0×107. The project involved modelling of the experimental facilities, to demonstrate proof of concept. The analysis shows that increasing the thermal response of the high pressure compressor (HPC) drum of a gas turbine engine assembly will reduce the drum time constant, thereby reducing the re-slam characteristics of the drum causing a reduction in the cold build clearance (CBC), and hence the reduction in cruise clearance. A further reduction can be achieved by introducing radial inflow into the drum cavity to further increase the disc heat transfer coefficient in the cavity; hence a further reduction in disc drum time constant.

Study of Oil Film Heat Transfer in Gas Turbine Engine Bearing Chamber

2021 ◽  
Author(s):  
Illia Petukhov ◽  
Taras Mykhailenko ◽  
Oleksii Lysytsia ◽  
Artem Kovalov
Keyword(s):  
Heat Transfer ◽  
Thermal Resistance ◽  
Gas Turbine ◽  
Gas Turbine Engine ◽  
Flow Core ◽  
Two Phase ◽  
Turbine Engine ◽  
Oil Film ◽  
Phase Medium ◽  
Engine Bearing

Abstract A clear understanding of the heat transfer processes in a gas turbine engine bearing chamber at the design stage makes it possible to properly design the lubrication and sealing systems and ensure the future bearing safe operation. The heat transfer coefficient (HTC) calculated based on the classical Newton-Richman equation is widely used to represent the heat transfer data and useful for the thermal resistance analysis. However, this approach is only formally applicable in the case of a two-phase medium. While there is a need to model a two-phase medium, setting the flow core temperature correctly in the Newton-Richman equation is an issue that is analyzed in this study. The heat from the flow core is transferred to the boundary of the oil film on the bearing chamber walls by an adjacent air and precipitating droplets. The analysis showed that droplet deposition plays a decisive role in this process and significantly intensifies the heat transfer. The main contribution to the thermal resistance of internal heat transfer is provided by the oil film. In this regard, the study considers the issues of the bearing chamber workflow modeling allowing to determine the hydrodynamic parameters of the oil film taking into account air and oil flow rates and shaft revolutions. The study also considers a possibility to apply the thermohydraulic analogy methods for the oil film thermal resistance determination. The study presents practical recommendations for process modeling in the bearing chamber.

Review of the von Karman Institute Compression Tube Facility for Turbine Research

2013 ◽  
Author(s):  
G. Paniagua ◽  
C. H. Sieverding ◽  
T. Arts
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Measurement Techniques ◽  
Gas Turbine Engine ◽  
Modern Technology ◽  
Forced Response ◽  
Engine Operation ◽  
Turbine Engine ◽  
Von Karman ◽  
Von Kármán

Advances in turbine-based engine efficiency and reliability are achieved through better knowledge of the mechanical interaction with the flow. The life-limiting component of a modern gas turbine engine is the high-pressure (HP) turbine stage due to the arduous environment. For the same reason, real gas turbine engine operation prevents fundamental research. Various types of experimental approaches have been developed to study the flow and in particular the heat transfer, cooling, materials, aero-elastic issues and forced response in turbines. Over the last 30 years short duration facilities have dominated the research in the study of turbine heat transfer and cooling. Two decades after the development of the von Karman Institute compression tube facility (built in the 90s), one could reconsider the design choices in view of the modern technology in compression, heating, control and electronics. The present paper provides first the history of the development and then how the wind tunnel is operated. Additionally the paper disseminates the experience and best practices in specifically designed measurement techniques to both experimentalists and experts in data processing. The final section overviews the turbine research capabilities, providing details on the required upgrades to the test section.

Thermo Fluid Dynamic Analysis of a Gas Turbine Transition-Piece

2014 ◽  
Author(s):  
Riccardo Da Soghe ◽  
Cosimo Bianchini ◽  
Antonio Andreini ◽  
Lorenzo Mazzei ◽  
Giovanni Riccio ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Gas Turbine ◽  
Fluid Dynamic ◽  
Gas Turbine Engine ◽  
Operating Conditions ◽  
Thermal Loads ◽  
Turbine Engine ◽  
Transition Piece

The transition-piece of a gas turbine engine is subjected to high thermal loads as it collects high temperature combustion products from the gas generator to a turbine. This generally produces high thermal stress levels in the casing of the transition piece, strongly limiting its life expectations and making it one of the most critical components of the entire engine. The reliable prediction of such thermal loads is hence a crucial aspect to increase the transition-piece life span and to assure safe operations. The present study aims to investigate the aero-thermal behaviour of a gas turbine engine transition-piece and in particular to evaluate working temperatures of the casing in relation to the flow and heat transfer situation inside and outside the transition-piece. Typical operating conditions are considered to determine the amount of heat transfer from the gas to the casing by means of CFD. Both conjugate approach and wall fixed temperature have been considered to compute the heat transfer coefficient, and more in general, the transition-piece thermal loads. Finally a discussion on the most convenient heat transfer coefficient expression is provided.

scholarly journals Supply of additional working fluid to the flow part of the NK-8 gas turbine engine

2020 ◽  
Vol 178 ◽  
pp. 01038
Author(s):  
George Marin ◽  
Dmitrii Mendeleev ◽  
Boris Osipov ◽  
Azat Akhmetshin
Keyword(s):  
Gas Turbine ◽  
Maximum Load ◽  
Constant Load ◽  
Gas Turbine Engine ◽  
Working Fluid ◽  
Turbine Engine ◽  
Power Turbine ◽  
Mixing Chamber ◽  
Flow Part ◽  
Turbine Installation

Modern energy development strategies of advanced countries are based on the construction of gas turbine units which is associated with sufficiently high values of thermal efficiency and a relatively short term for putting them into operation. In this paper, the NK-8 engine is considered. It is modernized with a mixing chamber and a power turbine for the purpose of its ground application. A study was conducted of the injection of an additional working fluid into the flow part of a dual-circuit gas turbine engine. Steam is used as an injectable substance. For research a mathematical model was created in the AS «GRET» software package. The studies were carried out under constant load, the maximum load during injection was determined. An additional worker can be supplied with summer power limitations when it is necessary to increase the power of a gas turbine installation. Studies have shown that the maximum power that can be obtained by supplying steam to the flow part is 32.2 MW.

Sign in / Sign up

Export Citation Format

Share Document