Shock Loss Research Articles

Shock losses and Pitot tube measurements in non-ideal supersonic and subsonic flows of Organic Vapors

The present work documents extensive experimental campaigns involving the first ever L-shaped Pitot tube measurements in non-ideal subsonic and supersonic flows of siloxane MM (hexamethyldisiloxane, C6H18OSi2), a fluid commonly employed in high-temperature Organic Rankine Cycles (ORCs).The objective is to establish reliable methodologies for pressure probes usage in flows relevant to ORCs, contributing to power generation efficiency through the improvement of current components design and plant regulation capabilities.Experimental campaigns were carried out on the Test-Rig for Organic Vapors (TROVA) at Politecnico di Milano, with a total-static Pitot tube designed according to ISO 3966, in non-ideal subsonic flows at Mach numbers M=0.2,0.5 with total pressure and temperature in the range PT=1−7bar, TT=195−205°C and a corresponding compressibility factor ZT≥0.8. Adequate performance of the complete system was verified and Pitot tube behavior was found to be unaffected by flow non-ideality, requiring no calibration in the investigated conditions.A simple Pitot tube was then employed for direct total pressure loss measurements across normal shock waves in non-ideal supersonic flows at M≃1.5, with total conditions of PT=1.5−12.8bar, TT=212−233°C and ZT≥0.66. The good agreement between measured losses and theoretical ones calculated from conservation equations attests the validity of the developed methodologies even with supersonic flows.

The Influence of Steady Air Jet on the Trailing-Edge Shock Loss in a Supersonic Compressor Cascade

To effectively reduce shock wave loss at the trailing edge of a supersonic cascade under high back-pressure, a shock wave control method based on air jets is proposed. The air jet was arranged on the pressure side of the blade in the upstream of the trailing-edge shock. The flow control mechanism and effects of parameters were analyzed by computational methods. The results show that the air jet formed an oblique shock wave in the cascade passage which decelerated and pressurized the airflow. The resulting expansion wave downstream of the jet slot weakened the strength of the trailing-edge shock. This could effectively change the normal shock into oblique shock and thus weaken the shock loss. Optimal control effect was achieved when the mass flow rate ratio of the jet to the passage airflow remained 0.35–1.11% and the distance from the jet slot to the shock foot of the trailing-edge shock was about five times the thickness of the boundary layer. The proposed method can reduce the total pressure loss of a supersonic cascade, with the maximum improvement effect reaching 7.29% compared to the no-control state.

Predictive value of tachycardia for mortality in trauma-related haemorrhagic shock: a systematic review and meta-regression

ObjectivesHeart rate (HR) is one of the physiological variables in the early assessment of trauma-related haemorrhagic shock, according to Advanced Trauma Life Support (ATLS). However, its efficiency as predictor of...

A Shock Loss Reduction Method Using a Concave Suction Side Profile for a Zero Inlet Swirl Turbine Rotor

Abstract A zero inlet swirl turbine rotor (ZISTR) works with axial inlet gas flow directly exhausted from a combustion chamber without any upstream vanes. The suction side trailing edge shock of the ZISTR generates a significant amount of aerodynamic loss. A shock loss reduction method is presented for the ZISTR. The principle of the method is to replace the single shock by double shocks. For minimizing the shock loss, the strength of the double shocks is set to be equal. This is based on a design criterion that multiple shocks should be with equal strength to achieve the minimum shock loss. This design criterion has been widely used for supersonic inlet design, but it is first extended to the transonic turbine design in the present article. A shock model, using aerodynamic relations of oblique shock, is put forward to quantitatively determine the shape of the concave suction-side profile. Numerical simulations indicate that the concave suction-side profile induces a new shock upstream of the suction-side trailing edge shock, and these two shocks are with nearly equal strength in the improved ZISTR. The shock loss of the improved ZISTR is obviously reduced. The concave tip profile would redistribute the blade load on the tip and increase the tip leakage flow loss. Hence, it is suggested that the concave profiles should be designed between 0% and 80% blade span, and the tip profile should keep unchanged. The improved ZISTR with an unchanged tip profile achieves an improvement of turbine efficiency by 0.8% at the design condition.

Mode transition analysis of a turbine-based combined-cycle considering ammonia injection pre-compressor cooling and variable-geometry ram-combustor

Mode transition (MT) is a significant process in the turbine-based combined-cycle (TBCC) involving the co-operation of high-speed and low-speed channels. To improve the thrust pinch caused by the deviation of the turbine and ramjet from the design point, a novel TBCC engine with ammonia mass injection pre-compressor cooling (Ammonia MIPCC) and variable-geometry ram-combustor (VGRC) is used to extend the operation envelope of the MT. CFD simulations and shock loss calculations are used to construct combined dual-channel inlet model. Through simulation, we find that the Ammonia MIPCC can reduce the pre-compressor temperature, improve the compressor efficiency, and increase the turbine's specific thrust. Meanwhile, increasing the ramjet combustor expansion ratio (CER) helps to alleviate the inlet unstart and extend the low-speed operating boundary of the ramjet. Furthermore, the extension of the operating envelope for TBCC under the effects of ammonia injection and CER is investigated. Based on specific thrust and specific impulse, the optimal starting Mach number field for MT process is studied, and the corresponding TBCC thrust is given. Overall, the results show that the optimal starting Mach number field for the MT of the proposed TBCC is 2.85–3.2, and two-stage sub-engines have high thrust performance in this range.

Conceptual Errors in Actuator Disc Theory and Betz’s Law for Wind Turbines

This paper started with the explanation of the conditions for using the momentum equation and with the presentation of the actuator disc theory. Focusing on the flow model used in actuator disk theory, both the Froude-Rankine theorem and Betz’s law have been examined. It has been found that the Froude-Rankine theorem is not justified because a stream-tube that is used as the control volume does not really exist (pseudo stream-tube). The theorem is also not justified because an unfounded velocity (v2) is used to connect the thrust of the actuator disc with the total power loss. Two flaws have been identified in Betz’s law. First, the use of both the unjustified Froude-Rankine theorem and the incorrect flow model totally violates the condition of determining the thrust of the actuator disc using the momentum equation. Second, the unfounded velocity (v2) from the Froude-Rankine theorem is misinterpreted and used for the volumetric flow rate through the actuator disc. These two main flaws lead to diverse computational contradictions and paradoxes, particularly when considering the case of an impermeable circular disc. The flaws in Betz’s law become evident when the law is applied to a rectangular actuator plate of infinite length. The possible solution for the actuator disc flow has been presented. This includes the additional consideration of energy dissipation in the flow downstream of the actuator disc, similar to the method used to calculate the Borda-Carnot shock loss.

Shock loss measurements in non-ideal supersonic flows of organic vapors

This paper presents the first ever direct measurements of total pressure losses across shocks in supersonic flows of organic vapors in non-ideal conditions, so in the thermodynamic region close to the liquid–vapor saturation curve and the critical point where the ideal gas law is not applicable. Experiments were carried out with fluid siloxane MM (hexamethyldisiloxane, C_6H_{18}OSi_2), commonly employed in medium-/high-temperature organic Rankine cycles (ORCs), in the Test Rig for Organic VApors (TROVA), a blowdown wind tunnel at the Laboratory of Compressible fluid dynamics for Renewable Energy Applications (CREA lab) of Politecnico di Milano. A total pressure probe was inserted in superheated MM vapor flow at Mach number sim 1.5 with total conditions in the range 215-230~^circ hbox {C} and 2-12~hbox {bar} at varying levels of non-ideality, with a compressibility factor evaluated at total conditions between Z_text {T}=0.68-0.98. These operating conditions are representative of the first-stage stator of ORC turbines. Measured shock losses were compared with those calculated from pre-shock quantities by solving conservation equations across a normal shock, with differences always below 2 % attesting a satisfactory reliability of the implemented experimental procedure. An in-depth analysis was then carried out, highlighting the direct effects of non-ideality on shock intensity. Even at the mildly non-ideal conditions with Z_text {T}gtrsim 0.70 considered here, non-ideality was responsible for a significantly stronger shock compared to the ideal gas limit at same pre-shock Mach number, with differences as large as 6%.Graphical abstract

Parametric Research and Aerodynamic Characteristic of a Two-Stage Transonic Compressor for a Turbine Based Combined Cycle Engine

This paper researches the parametric optimization of a two-stage transonic compressor having a large air bypass at partial rotating speed according to flow analysis for a turbine-based combined cycle engine (TBCC). To obtain adequate thrust, the inlet transonic compressor of the turbofan part of the TBCC is required to have a wider frequently used corrected rotating speed range and a larger mass-flow rate at low rotating speed, which is different from a typical transonic compressor. The one-dimensional blade design parameters and flow path of the baseline two-stage transonic compressor are introduced. With the widely used CFD software Numeca, the three-dimensional flow fields of the baseline transonic compressor and effects of the flow path between Stage 1 and Stage 2 on the inlet mass flow rate are analyzed for indicating the further improvement direction. For design speed (NC = 1.0), to improve the efficiency at the design point, parametric research is carried out on Rotor 2 to optimize the shock structure and strength, resulting in enhanced efficiency at the design point due to reduced shock loss of Rotor 2. For partial speed (NC = 0.8 and 0.7), since the flow field analysis indicates that the flow blockage in S1 limits the entire mass flow rate, the parametric redesign of stator S1 aims at obtaining an increased blade throat width to enhance the flow capacity of S1. Simulation confirms the increase in the mass-flow rate and efficiency at partial speed due to the reduction in flow blockage and related viscous losses. Aerodynamic analysis at representative operation points indicates that the modifications of R2 and S1 lead to obvious aerodynamic improvement at all rotating speeds (NC = 1.0 to 0.7), while maintaining sufficient stall margin.

Numerical Investigation on the Performance of a Transonic Axial Compressor with Inlet Distortion and Low Reynolds Number

The performance and stability of the transonic fan stage with a nonuniform inflow is a key issue in aero engine operation, and the coupling of inlet distortion and low Reynolds numbers at high altitude creates more severe challenges to aero engines. This work used computational methods to explore the performance and stability of a transonic fan stage with inlet distortion and a low Reynolds number. To investigate this issue, the transonic fan stage NASA stage 67 with a 180° total pressure distortion at a low Reynolds number was selected as the test case. Full-annulus 3D unsteady simulations were conducted to reveal the details of the flow field under coupling conditions. The computational results under different conditions were analyzed and showed that the coupling effect was not linearly stacked with single factors. The low Reynolds number in the coupling case thickened the boundary layer on the blade surface, and, on the one hand, the profile loss in the hub region increased. On the other hand, the structure of shock wave was converted in the tip region, which increased the shock loss significantly. In addition, the variation in the shock wave structure reconstructed the pressure distribution on the blade surface, allowing the fluid to migrate to the tip region, which affected the tip flow structure and ultimately delayed the stability boundary.

Influence of Solidity on Aerodynamic Performance of Axial Supersonic Through-Flow Fan Cascades

To determine the effects of solidity on its aerodynamic performance and key flow structures, this study reports numerical simulations of the cascades of an axial supersonic through-flow fan with an inlet Mach number of 2.36 over a 15 deg range of incidence. The results indicate that, as the solidity increased, the overall loss first dropped and then increased. At the design incidence, loss at optimal solidity was 78% lower than the maximum loss. The overall loss was heavily dependent on the solidity but insensitive to incidence, especially at low solidity. At a critical solidity (2.38), the shock at the leading edge on the pressure side impinged on the suction surface near the trailing edge. At the optimal solidity, the wake loss was minimized and the number of reflected shocks decreased. The wake loss can be reduced by causing the shock to impinge on the suction surface near the throat of the passage. Moreover, this shock loss can be controlled by weakening its intensity. While reducing the local separation induced by the shock/boundary-layer interaction is ineffective for simultaneously reducing the loss of viscosity, reducing the loss of friction dominated by the surface area of the blade per unit of mass flow is effective.

Kiel Probes for Stagnation Pressure Measurement in Rotating Detonation Combustors

Kiel probes have the potential to be a versatile tool for determining stagnation pressure gain in rotating detonation combustors (RDCs), accompanying the commonly used equivalent available pressure method. Although average pressure gain values determined with Kiel probes are comparable to those from thrust stand experiments, one can expect several sources of measurement error from the unsteady trans- and supersonic environment. This work investigates the response of a Kiel probe in highly unsteady flow, similar to what would be encountered in an RDC. The probe is subjected to an underexpanded starting jet behind an incident shock with Mach numbers of 1.6–2.7, emanating from a shock tube with a reservoir ratio of about 394. The incidence angle of the probe is varied between 0 and 90 deg, as is the probe’s axial location with respect to the tube’s exit plane. High-speed schlieren images reveal the Mach number of the moving shock wave and the structure of the detached bow shock at the Kiel head, which is similar to that of a bluff body. It is shown that the measured stagnation pressure signal is independent of inflow angle over a range of , and that signal attenuation is caused by gas processing through the bow shock and viscous losses in the probe’s capillary. The frequency response of the Kiel probe to sinusoidal, small-amplitude pressure fluctuations is determined in an acoustic calibration facility up to 5500 Hz, confirming linear behavior and that no unwanted resonance is present in the probe. A Berg–Tijdeman representation delivers amplitude ratio and phase lag of comparable magnitude. An assessment of representative boundary conditions reveals that the average stagnation pressure measurement error is of the order of 1%.

A Comprehensive Analytical Shock Loss Model for Axial Compressor Cascades

AbstractThe approach applied in various research papers that model compressor shock losses is valid only for certain types of airfoil cascades operating in a narrow range of working conditions. Lately, more general shock loss models have been established that cover a wider variety of airfoils and operating regimes. However, owing to the complexity of the studied matter, the majority of such models are, to a certain extent, presented only in a descriptive manner. The lack of specific details can affect the end results when such a model is utilized since improvisation cannot be avoided. Some models also apply complex numerical procedures that can slow the calculations and be a source of computational instability. In this research, an attempt has been made to produce an analytical shock loss model that is simple enough to be described in detail while being universal and robust enough to find wide application in the fields of design and performance analysis of transonic compressors and fans. The flexible description of airfoil geometry encompasses a variety of blade shapes. Both unchoked and choked operating regimes are covered, including a precise prediction of choke occurrence. The model was validated using a number of numerical test cases.

Choking dynamic of highly swirled flow in variable nozzle radial turbines

This paper presents the results of a computational investigation of the aerodynamic choking mechanism in a variable geometry turbine, which is widely used in automotive turbocharging. RANS and URANS numerical simulations were carried out for two stator vane positions, 10% and 30% opening at different speeds and several other operating conditions to observe the establishment of choked flow and rotor-stator interactions. When the stator vanes are at a closed position and high-pressure ratio, a shock wave is developed on the suction side of the stator vane; moreover, the effective area extends toward the rotor inlet. The shock losses of a fluid particle upstream of the rotor are related to the number of shocks that the particle goes through. The pressure losses are high close to the stator vanes and start to decrease toward the center of the vaneless space until they start to increase close to the rotor. The interaction between the rotor and stator creates shocks waves with an intensity depending on the rotor's leading edge position and the rotational speed. The pressure profile of the rotor blade under this circumstance is also affected, especially at high rotational speeds, when important load fluctuations may affect the integrity of the blades.

Efficacy and safety of percutaneous nephrolithotomy combined with negative pressure suction in the treatment of renal calculi: a systematic review and meta-analysis.

BackgroundWith advances in medicine, there have been more and more ways to treat renal calculi in recent years. Percutaneous nephrolithotomy (PCNL) is a safe and effective treatment. The purpose of this paper is to study the efficacy and safety of PCNL combined with negative pressure suction in the treatment of renal calculi by meta-analysis.MethodsThe PubMed, EMBASE, Cochrane Library, Chinese Journal Full-Text Database, VIP, Wanfang Science and Technology Journal Full-Text Database, and Chinese Biomedical Literature Search databases were searched for articles related to the efficacy and safety of PCNL combined with negative pressure suction in the treatment of renal calculi from the establishment of the databases to October 2021. Endnote X9 software was first used to check and eliminate the articles, and the quality of the included articles were evaluated according to the risk of bias tool of Cochrane Collaboration. Stata 15.1 software was used to record the data. A meta-analysis was performed on the stone clearance rate, operation time, postoperative complications, postoperative fever, septic shock, intrapelvic pressure, and blood loss of PCNL combined with negative pressure suction in the treatment of renal calculi. The reliability of the results was assessed by a sensitivity analysis. Egger’s linear test was used to test the publication bias of the articles.ResultsA total of 10 articles were included in the meta-analysis, and the total sample size of the study was 820. The meta-analysis showed that when PCNL combined with negative pressure suction was used to treat renal calculi, the stone clearance rate and the occurrence of septic shock of the test group did not differ significantly from that of the control group; the incidence rate of postoperative complications、the operation time, the intraoperative bleeding and the postoperative fever of the test group was significantly better than that of the control group.DiscussionCompared to the group without negative pressure, PCNL reduces the operation time, postoperative complications, postoperative fever, septic shock, and intraoperative blood loss without increasing the risk of septic shock.

NUMERICAL INVESTIGATION ON FLOW ACROSS STRUT-BASED FLAME HOLDER WITH CONVERGING GROOVES

The flow across a modified strut-based flame holder is numerically analyzed using the two-equation Menter SST k-ω turbulence model. The modified strut geometry contains alternative converging cavities and ramps on the top side. This design superimposes the advantages of cavity flame holders into strut-based flame holders. The effect of Mach number, the variation in geometrical parameters such as the length of the ramp, depth of the cavity and convergence angle of the cavities are extensively studied. The numerical simulations were conducted using a commercial software ANSYS FLUENT. The validation of the code is accomplished using an available experimental data for a simple strut configuration with fuel injection. The numerical predictions bear a close resemblance with the experimental data. As the Mach number of the flow is varied, the flow structures obtained is consistent with the flow physics. Different ramp lengths and cavity depths were analyzed to determine the behaviour of the flow. The shorter ramp length seems to carry a higher turbulence rate downstream of the flame-holder. Moreover, by increasing the depth of the cavity larger rate of production of turbulent kinetic energy is achieved in the cavity. The variation in convergence angle of the cavity also helps to impart velocity reduction downstream of the strut. The velocity reduction without shock losses is desirable for a supersonic combustor. The present study reveals that the same can be achieved by increasing the convergence angle of the cavity

Maximum Thickness Location Selection of High Subsonic Axial Compressor Airfoils and Its Effect on Aerodynamic Performance

Solidity and camber angle are key parameters with a primary effect on airfoil diffusion. Maximum thickness location has a considerable impact on blade loading distribution. This paper investigates correlations of maximum thickness location, solidity, and camber angle with airfoil performance to choose maximum thickness location quickly for compressor airfoils with different diffusion. The effects of maximum thickness location, solidity, and camber angle on incidence characteristics are discussed based on abundant two-dimensional cascade cases computed through numerical methods. Models of minimum loss incidence, total pressure loss coefficient, diffusion factor, and static pressure rise coefficient are established to describe correlations quantitatively. Based on models, dependence maps of total pressure loss coefficient, diffusion factor, and static pressure rise coefficient are drawn and total loss variation brought by maximum thickness location is analyzed. The study shows that the preferred selection of maximum thickness location can be the most forward one with no serious shock loss. Then, the choice maps of optimal maximum thickness location on different design conditions are presented. The optimal maximum thickness locates at 20–35% chord length. Finally, a database of optimal cases which can meet different loading requirements is provided as a tool for designers to choose geometrical parameters.

Case Report on Post Operative Case of Exploratory Laparotomy for Ruptured Ectopic Pregnancy with Septicemia

Introduction: Extra uterine pregnancy is a first-trimester pregnancy problem that affects 1.3–2.4 percent of all pregnancies. The key signs of the ectopic pregnancy are abdominal discomfort and vaginal bleeding along with Sharp, dull, or cramping pains may be experienced around 50% of the women who are suffering from ectopic pregnancy. The neglected ectopic pregnancy may results in the fallopian tube can burst, internal abdominal bleeding, shock, and serious blood loss and later complication is septicemia. As a health care professional it’s very important to manage certain complication with medical and surgical management.
 Main Symptoms and/or Important Clinical Findings: A 20 years old female with post operative case of Exploratory Laparotomy admitted in A.V.B.R.H. on 14/02/2021.with chief complaints of the after undergone certain investigation she has diagnosed as Exploratory Laparotomy with septicemia as post-op complication.
 The Main Diagnoses, Therapeutic Interventions, and Outcomes: A 20 years old female with post-operative Exploratory Laparotomy for Ruptured Ectopic Pregnancy operated case with septicemia, with chief complaints of acute abdominal pain, and vaginal bleeding the doctors manage her initially with I.V. fluids, antibiotics, Zonac suppository and adequate nursing management.
 Nursing Perspectives: The nursing interventions initiated for managing present case are fluid replacement therapy, monitoring vital sign per hourly, monitoring the CBC reports and other investigations like USG abdomen, blood glucose levels. Maintained TPR Chart, I/O Charting, abdominal girth charting.
 Conclusion: In the Present case the patient of A 20 year old female with post operative exploratory laparotomy for ruptured ectopic pregnancy with septicemia it has been managed with the therapeutic and surgical treatment ,right now the patient condition then patient has discharged on dated 22/2/21.

Optimization Study of Guide Vanes for the Intake Fan-Duct Connection Using CFD

The connection between an intake fan and a ventilation shaft must be designed in such a way that it minimizes the energy waste due to singularity losses. As a result, the questions of which radius of curvature to use and if guide vanes have to be included need to be answered. In that case, the variables such as the number, upstream and downstream penetration length, radius of curvature, and width of the vanes, need to be defined. Although this work is oriented to mine ventilation, these questions are usually valid in other engineering applications as well. The objective of this study is to define the previously mentioned variables to determine the optimal design combination for the radius/diameter relationship (r/D). Computational fluid dynamics was used to determine the shock loss factor of seven elbow curvature ratios for a 3 m diameter duct and fan, with and without guide vanes to estimate the best performing configuration and, therefore, to maximize the fan airflow volume. The methodology used consisted of initially developing models in 2D geometries, to optimize the meshing and the CPU use, and studying separately the number of vanes, upstream and downstream penetration, radius of curvature, and width of the vanes for each curvature ratio (r/D). Then, the best-performing variable combinations for each curvature ratio were selected to be simulated and studied with the 3D geometries. The application of the guide vane designs for three-dimensional simulated geometries is presented, first without and then with guide vanes, including the shock loss factors obtained. The methodology and obtained results allowed quantifying the energy savings and to reduce the CFD simulations steps required to optimize the design of the elbow and guide vanes. The results obtained cannot be used with elbows in exhaust fans, because fluid dynamics phenomena are different.

New approach of inverse design of transonic compressor rotor blade via prescribed isentropic Mach distributions without modification of governing equations

Shock loss is the primary source of total pressure loss of transonic axial compressors. Reducing the shock by redesigning the geometry of rotor is of great interest for turbomachinery designers. However, the complex flow field involving shock waves, shock-boundary interaction, intense secondary flows, etc., in the compressor makes the design of rotor difficult. The conventional method of design and optimization is computationally intensive and time-costly. This study introduces an inverse design method to design rotor blades corresponding to prescribed isentropic Mach number distributions with no modification of flow-governing equations. An artificial neural network is trained to predict the isentropic Mach number distributions of any deformed blades. Then, with the pattern search optimization, the blade corresponding to the prescribed isentropic Mach number distributions can be achieved. When the aerodynamic parameter database is calculated and the neural network is obtained, this method can design large numbers of blades of changed isentropic Mach number distributions immediately, without modifying the computational fluid dynamics (CFD) flow solver. The design process is fully automatic and efficient. In this study, NASA Rotor 37 is redesigned and optimized as test cases. Some analysis on the influence of blade shape on aerodynamic characteristics of the rotor is represented in this study.

Professionalization of Political Campaigns: Roadmap for the Analysis

Political parties in developed democracies have undergone deep inner transformation processes brought about by changes in voting behaviour of their electorates, fragmentation of media landscape, and technological revolution. Such changes have caused that the topic of political party transformation has become a central focus of current political science research. However, only a few works have addressed specific aspects of these far-reaching transformations, that is the process of modernisation and professionalization of political campaigns. Specifically, the recent research on professionalization of electoral campaigns has focused primarily on measurement of the index of professionalization, which is suitable for comparative research. Yet deep understanding of the process itself has been still absent, and therefore, this research paper aspires to cover this gap. Main goal of this paper is to offer a roadmap for analysis of professionalization of electoral campaigns with focus on qualitative studies. It represents a causal mechanism of professionalization of electoral campaigns, including the identification of internal and external factors and possible framework conditions that contribute to it (i.e. professionalization), through the process of tracing method (i.e. the causal mechanism is built on the basis of the process tracing method). Here, external factors are defined as environmental conditions, which include declining voter turnout, declining party identification, increasing electoral volatility, and declining interest in political party membership. Although their effect is considered a long-term one, the causal mechanism assumes their influence on the triggering of other processes: external shock (electoral win or loss) and internal shock (change of leader). In the next part of the causal mechanism, subsequent internal processes are expected in the form of changes to the primary goal and organizational structure of parties. Unlike previously published works on this topic, this paper suggests that not only the specific internal and external factors or amount of invested financial resources affect the degree of professionalization, but also the party's market orientation and the level of its internal discipline.