Axial compressor stall and surge prediction by measurements h. Study of compressor instabilities such as surge and rotating stall has received much attention in recent years. Modification of axialflow compressor stall margin by. These factors may aggravate to a state of local breakdown of flow or a total breakdown of flow or with a. Compressor stall and surge university of cambridge. Infinalform 10 july 1997 the paper deals with experimental investigations and analyses ofunsteady pressure distributionsin different. Use features like bookmarks, note taking and highlighting while reading compressor surge and rotating stall. Once the higher pressure overcomes the loss of pressure from a stalled stage than the air will reverse itself and come forward out of the inlet with a loud bang. This can happen at startup, during rapid acceleration from low rpm, or during a sudden reduction of mass airflow, when a few or all the stages. Modern compressors are carefully designed and controlled to avoid or limit stall within an engines operating range.
A stall condition is caused by a pressure ratio that is incompatible with the engine rpm. Compressor stall recovery through tip injection assessed. The effect of several inlet geometries on compressor performance is investigated. Watch an f16 suffer a compressor stall during the display. Pdf modeling and control of surge and rotating stall in. Surge description flow reverses in 20 to 50 milisec. A particular kind of stall is the socalled compressor surge is a complete breakdown in compression that occurs when compressors blades stall airfoils just like an airplane wing stalls. This is the first of a threepart series by the author.
The surge usually starts in one stage of a multistage compressor and can occur very rapidly. Compressor stall aircraft turbine engine aviation glossary. Compressor surge and stall detection and prevention tips. The work is motivated by the fundamental instability problem of surge and rotating stall which limits the range of operation for compressors at low mass flows. Compressor stall a compressor stall is a local disruption of the airflow in a gas turbine or turbocharger compressor. Modeling and control advances in industrial control.
Surging and stalling both lead to unstable flow in compressors. Surge is violent instability characterized by onedimensional fluctuation in. Stall recovery at a fixed throttle setting dashed lines occurs 0. Find out information about compressor stallmargin curve. Centrifugal compressor surge, modeling and identification. The severity of the phenomenon ranges from a momentary power drop barely registered by the engine instruments to a complete loss of compression in case of a surge. Compressor stallin the worst case scenario the aviationist. A compressor stall is a situation of abnormal airflow resulting from a stall of the aerofoils within the compressor of a jet engine. The surge can result in a condition known as compressor stall, which stops the compressor and can cause serious damage. Compressor surge and stall ronald c pampreen published in 1993 in norwich by concepts eti services. A compressor surge control system linkedin slideshare.
An operating curve of a gas turbine engine, which shows the relationship. In the vicinity of the stall line, the flow field is inherently unsteady due to the interactions between adjacent rows of blades, formation of small stall cells, flow separation and the viscous effects including shockboundary layer interactions. Compressor surge and stall ghent university library. The compressor system instability and control have been an inherently challenging problem for turbomachinery community since the advent of the gas turbine engine. Several surge cycles can occur due to delays and lags in high temperature, thrust, and vibration shutdown systems. The closer the operating point is to the surge line, the greater the pressure ratio achieved by the compressor, but the greater the risk of stall or surge. During the display at the zeltweg airshow in austria, the belgian air force f16 suffered a compressor stall that caused a loud bang and an impressive backfire. Compressor loadsharing control and surge detection. Professional development program compressor surge and stall. Effect of the inlet geometry on performance, surge margin.
Surge is a complete breakdown of steady flow through the compressor. When a centrifugal compressor surges, there is an actual reversal of gas flow through the compressor impeller. Surge is a system dependant phenomenon associated to large amplitude oscillations of the pressure through the compressor system 1. An improperly designed surge control system can lead to multiple surge events increasing the risk to personnel safety and major damage to the compressor. The phenomena of stall and surge in axialcentrifugal compressors is in vestigated through highresponse measurements of both the pressure. In this case, the problem is caused by unexpectedly high pressure in the combustion chamber or in the compressor, which forces its way forward as well as backwards, against the incoming flow rate. Unsteady compressor operating point at design speed during stall inception and stall recovery. This occurs when the angle of attack of the blades of the compressor exceed their critical angle of attack resulting in one or more stages of rotor blades failing to pass air smoothly to the succeeding stages. A surge is unique to the engine which has a higher pressure contained behind the compressor which is stalling. Engine compressor will stall if the compressor is operated above the surge line. Keywords axial compressor centrifugal compressor compression system compressor characteristic inlet guide vane. Compressor surge and stall compressor surge and stall ronald c. An investigation of surge in a highspeed centrifugal.
Cp5059 continual assessment ay202014 s2 dche 2a21 joshua miaoqi yihuan yunya. Compressor rotating stall, surge, and its control hindawi. Compressor stall article about compressor stall by the. A compressor going into stall is like jumping off a cliff with a bungee cord. If the bungee cord has no losses to dampen the oscillation, we have something akin to surge. What is surging choking and stalling in compressor mecholic. Mechanism of stall and surge in a centrifugal compressor. Surge control design for centrifugal compressor systems. Rotating stall is characterized by the presence of one or several cells rotating around the annulus, either in the impeller or in the diffuser. Rotating stall and surge, known as the typical flow instability for compressors, can be loosely characterized as the pressure breakdown as the mass flow decreases. Global stability and control analysis of axial compressor stall and surge phenomena using bifurcation methods n ananthkrishnan1,ugvaidya2andvwwalimbe3 1indian institute of technology bombay, powai, mumbai, india 2university of california, santa barbara, ca, usa 3georgia institute of technology, atlanta, ga, usa abstract.
Over the last 75 years these compressors have been improved continuously, today achieving component efficiencies of more than 90%. A compressor surge is flow through a compressor that is against the direction of flow during normal operation or an oscillating flow in both directions. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. An alternative type of stall is a compressor surge. The course of the surge is decreasing mass flow rate and increases a rotational speed of the impeller. Download it once and read it on your kindle device, pc, phones or tablets. Cumpsty 1989 and pampreen 1993 differentiate between progressive and abrupt stall, and full span or. Axialflow compressors are used in the majority of large gas turbines, both in powerplants and aircraft jet engines.
A compressor stall in a jet engine is a circumstance of abnormal airflow resulting from the aerodynamic stall of aerofoils compressor blades within the compressor. Modeling and control advances in industrial control kindle edition by gravdahl, jan tommy, egeland, olav. A stall that results in the complete disruption of the airflow through the compressor is referred to as a compressor surge. Now we will see how the surge starts in a compressor.
When the diffuser vane angle is adjusted positively which means the airflow incidence angle at the diffuser inlet increases, the aerodynamic load is increased, and the instability of the vaneless region between the impeller and the diffuser is. It is related to compressor surge which is a complete disruption of the flow through the compressor. This article explains surge phenomena and discusses why the antisurge protection system is a very important part of a compressor surge. Compressor surge and stall 1st edition by ronald c. The surge is starting with the instant flow reverses, shown in the above figure.
It is defined as the lower limit of stable operation of the compressor. Compressor stallmargin curve article about compressor. Stall is found in dynamic compressors, particularly axial compressors, as used in jet engines and turbochargers for reciprocating engines compressor stalls result in a loss of compressor performance, which can vary in severity from a momentary engine power drop. Modeling and control of surge and rotating stall in compressors. This was a test flight to find out why that engine had compressor stalls at altitude. An aerofoil stalls when the air flow completely separates from the top side or s. Sustain oscillation important element it protects the compressor from surge over the range of compressor operations. Study of compressor instabilities such as surge and rotating stall has received. Modification of axialflow compressor stall margin by variation of stationary blade setting angles john paul rukavina iowa state university follow this and additional works at. To understand the concept behind stalling and surging, we should first know the flow over an airfoil. A cd nozzle improves surge margin, isentropic efficiency and noise emissions. Global stability and control analysis of axial compressor. A condition in which the compressor blades stall as the relative airflow meets the blades beyond the critical angle.
It is a phenomena accompanied by centrifugal compressors having continuous flow rate, gas path inside compressor flows having an acceptable value of eddies and vortices but if these eddies and vortices. A compressor stall is a local disruption of the airflow in the compressor of a gas turbine or turbocharger. Pampreen 1973 found that the clearance loss of a centrifugal compressor can be. The mechanism of stall and surge in the compressor differs at different diffuser vane angles. The compressor blade on the right is in stalled condition. Active controllers that allow the compressor to operate safely at its.
The small pt6 will stall and surge at higher speeds if the bleed valve closes to early but will very often have no stall tendancy above about 92% when the valve is closed in other words it will be transient from the point of early closing to a point where the engine has reached a speed that the valve should be closed. There are many station events that can cause a centrifugal compressor to surge, such as interaction with other units, reciprocating compressor pulsations, and upset conditions like sudden. A compressor stall in a gas turbine engine is a condition in an axialflow compressor in which one or more stages of rotor blades fail to pass air smoothly to the succeeding stages. These instabilities lead the compressor to rotating stall or surge. Section 3 description of surge 31 surge versus stall surge is a dynamic instability that occurs in dynamic compressors. In the case of turbine engines, like jet airplane engines, a surge which. Compressor aerodynamic instabilities are generally categorized in two distinct classes. In addition, surge avoidance measures such as recycle and bleed have significant negative effects on energy consumption and should preferably be avoided kim and fleeter, 1994. Surge rotating stall in compressors dring thesis jan t omm y gra vdahl rep ort w departmen t of engineering cyb ernetics norw egian univ ersit y of science and t ec hnology n t rondheim norw a y. A tapered duct improves surge margin, isentropic efficiency and pressure ratio. The instability is characterized by large limit cycle oscillations in compressor. Honen institutjftr strahlantriebe undturboarbeitsmaschinen, rwthaachen aachen university oftechnology, 52062aachen, germany received3 april 1997. At low flow rates, rotating stall and surge are the fundamental limits of a compressors operating range.
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