Engineering Tuning Research Articles

A multi-objective co-optimization method of controller parameters for the overall system of small pressurized water reactor

Small pressurized water reactors (SPWRs) normally have complicated and varying working conditions, and become an important direction for nuclear energy development. The overall system of SPWR, including the reactor coolant average temperature control system, the feedwater control system of the once-through steam generator (OTSG), the steam turbine speed control system and the steam dump control system, is used to guarantee the safe and stable operation. The overall system of SPWR is designed with multiple PI controllers. To accomplish intelligent self-tuning of PI controller parameters, reduce the dependence on human engineering experience, and improve the control performance of the overall system, a multi-objective co-optimization method(MMOCO) with PI controller parameters for overall system of SPWR is proposed. Firstly, based on the coordinated control theory and PI control algorithm, the overall system of SPWR is established. Then, a MMOCO for the overall system of SPWR is designed with the Non-Dominated Sorting Genetic Algorithm-II (NSGA-II). Finally, to compare the performance of the controller parameters derived from the MMOCO and the controller parameters obtained via the engineering tuning method, step load decrease transients are selected. The results show that the ability to control the overall system of SPWR is effectively improved after applying the MMOCO.

Research on tracking and synchronization control of dual hydraulic cylinders based on improved active disturbance rejection control

To ensure the stability of vertical mold casting machine casting, and improve the quality of casting, for which the electro-hydraulic servo system of the traditional active disturbance rejection control(ADRC) of the nonlinear function is not smooth, a new type of nonlinear function is used. For the ADRC controller, there are too many adjustment parameters and complex engineering tuning, The snake optimization(SO) algorithm is used to adaptively tune the controller parameters, and the error can also be reduced. The simulation results show that compared with the PID controller and the traditional ADRC controller, the ADRC controller based on the Ifal function and SO has a certain jitter suppression effect as well as good tracking and synchronization performance, which can effectively improve the tracking and synchronization accuracy of the dual hydraulic cylinders of the electro-hydraulic servo system.

A Comparative Study and Improved Bearing Fault Classifier Using Raw Vibration Data Under Limited Training Samples

Artificial intelligence is gaining traction in bearing fault detection and diagnosis. Generally, signal processing and feature selection are carried out to facilitate the fault classification process; however, classification accuracy tends to degrade under limited training data. In this paper, various artificial intelligence (AI) classification models are studied and compared using raw vibration data without signal processing and feature engineering. A Cosine k-Nearest Neighbours (CosKNN)-based classification model is optimized by integrating a Segmentive Mechanism, resulting in an overall classification F1-score improvement to 90.8% compared to the original classifier's 76.9%. The comparative findings show that the proposed model is suitable for circumstances with limited availability of training data, signal processing tools, and feature engineering tuning.

Light on multi-mode optical properties of carbon dots through rational surface engineering tuning strategies

Carbon dots (CDs) materials are currently gaining significant attention for applications in bioimaging, fluorescent sensing, anti-counterfeiting, therapeutics, catalysis and other areas. However, efficient and attractive CDs with multi-mode luminescence and tunable spectra through simple modification strategy are still urgently needed for multifunctional optical applications and mechanism exploration. Herein, we demonstrate two rationally designed and completely different CDs surface tuning strategies, which can generate multi-mode optical properties including multi-color fluorescence (FL), room-temperature phosphorescence (RTP) and aggregation-induced emission (AIE). The optical properties after weak interactions modification are characterized by freedom and switchability, while the optical properties after strong interaction modification are characterized by compulsion and non-switchability. Moreover, it is further demonstrated that the cell imaging, light-emitting devices (LEDs), “and” logic gate and anti-counterfeiting applications based on multi-mode optical effects. This study not only provides a new model system for understanding the surface states of CDs, but also opens up opportunities for new applications of multi-mode optical materials for various purposes.

Self‐Assembled Nanofibrous Hydrogels with Tunable Porous Network for Highly Efficient Solar Desalination in Strong Brine

AbstractHydrogel‐based solar evaporators (HSEs) emerged as energy‐efficient designs for water purification due to the reduced vaporization enthalpy in the hydrated polymeric network. However, it remains challenging for HSEs to achieve stable performance in desalination, partly due to the tradeoff between desired evaporation dynamics and salt tolerance. Here, composite hydrogels with tunable self‐assembled nanofiber networks are exploited for the engineering of solar evaporators with both high evaporation performance and resistance to salt accumulation. The nanofibrous hydrogel solar evaporators (NHSEs) present an intrinsic open network with high porosity, above 90%, enabling continuous water channels for efficient mass transfer. Theoretical modeling captures the complex nexus between microstructures and evaporation performance by coupling water transfer, thermal conduction, and vaporization enthalpy during evaporation. The mechanistic understanding and engineering tuning of the composites lead to an optimum configuration of NHSEs, which demonstrate a stable evaporation rate of 2.85 kg m−2 h−1 during continuous desalination in 20% brine. The outstanding performance of NHSEs and the underlying design principles may facilitate further development of practical desalination systems.

Assessment of M15 Fuel on BS IV 2 and 3-Wheeler

Across the world, methanol is evolving as a clean, sustainable transportation fuel for the future. Methanol fuel is an alternative biofuel for internal combustion and other engines, either in combination with gasoline or independently. Methanol's high octane and oxygen content produces a cleaner burning gasoline which significantly reduces vehicle exhaust emissions. A lower boiling temperature for better fuel vaporization in cold engines, the highest H-C ratio for a lower carbon intensity fuel, and no Sulphur contamination which improves catalytic converter operation. In the paper, a study is carried out for the blend of 15% methanol (M15) with Gasoline on BS-IV vehicles and a comparison is done for the tailpipe emissions. A gap analysis of vehicles with E0 and M15 fuel is done with baseline emission testing along with full throttle performance of the vehicle to check the effect of oxygenated fuel (M15). The main purpose of this study is to analyze the impact of M-15 fuel on 2 and 3-wheeler vehicles in the as-is condition without any engine tuning and retaining the base gasoline (E0) settings.
 Keywords: M15 fuel, methanol, BS IV, blended fuel, tailpipe emission, hygroscopic, 2 and 3-wheelers, mass emission, fuel economy, NOx

Optimization of the Control of Electromagnetic Brakes in the Stand for Tuning Internal Combustion Engines Using ID Regulators of Fractional Order

This work is aimed at developing a stand for tuning the fuel system of an internal combustion engine based on two electromagnetic retarders connected to the driving wheels of a car to simulate a load, and a microprocessor-based torque control system for each brake. In accordance with the terms of reference from the specialists of the automotive service center, such a stand should provide two main modes of operation: (1) stabilization of the speed of the drive wheels in the entire range of loads (fuel supply); (2) engine acceleration and deceleration according to linear tachograms in the range from minimum to maximum speed to determine the dependence of engine power and torque on speed. The purpose of this research is the synthesis of controllers, testing, the choice of the structural scheme, and the parameters of the control and data processing system in the stand for the precision tuning of internal combustion engines. Based on a preliminary analysis of the system, taking into account the mechanical connection of the wheels through the main gear and the car differential, the nonlinear dependence of the electromagnetic torque on the current and retarder speed, and subsequent experimental results, we obtained two types of controller—a third-order aperiodic transfer function and a fractional aperiodic transfer function of order 1.6. This made it possible to synthesize a family of controllers that ensure the operation of the stand in the required modes: synchronization of wheel speeds during engine acceleration; stabilization of the reference speed when the engine torque is changed from minimum to maximum due to fuel supply; measurement of the maximum power and torque of the internal combustion engine during the formation of a triangular tachogram with a given acceleration to compensate for the dynamic component of the torque due to mechanical inertia. The system with the PID controller configured in MATLAB in the “Tune” package has the best performance, but the smallest overshoot and the best dynamic accuracy are ensured by the PIDIγIµ fractional–integral controller, where the system is characterized by a fractional order of astaticism 1.6. Such a controller for each electromagnetic retarder serves as the basis of the microprocessor-based control, data acquisition, processing, graphical display system, and will also be used to develop a similar bench for tuning four-wheel-drive vehicles.

Enhancing photocatalytic nitrogen fixation performance of Co-doped bismuth molybdate through band engineering tuning

Energy band engineering strategy by doping has been extensively proved to have great influence on photocatalytic properties of semiconductors. Herein, a novel Co-doped Bi2MoO6 (Co-BMO) photocatalyst was developed for photocatalytic nitrogen fixation. Co-BMO with microsphere structure was synthesized by a one-step solvothermal method. The NH3 yield of 0.3 % Co-BMO (130.07 μmol·h−1·gcat−1) was about 3.9 times higher than that of pure BMO without scavengers and visible light irradiation. The band gap of 0.3 % Co-BMO was reduced and the average PL lifetime was improved due to the successful doping of Co2+, which directly led to higher separation efficiency of photogenerated carriers and improved photocatalyst activity. In addition, gas chromatography (GC) tests showed that 0.3 % Co-BMO had a higher photocatalytic oxygen production capacity, which meant that more protons would be involved in the nitrogen reduction reaction. Their synergistic effect greatly enhanced the photocatalytic nitrogen fixation ability of 0.3 % Co-BMO. This novel photocatalyst may be a promising candidate for photocatalytic nitrogen fixation.

Application of Boiler Optimization Monitoring System Based on Embedded Internet of Things

In order to study the deficiency of tuning PID controller in traditional boiler combustion air system, this paper proposes an embedded Internet of things monitoring system and puts forward a method of fuzzy PID controller with the help of nonlinear optimization algorithm to reasonably set the initial value of control parameters. Through the simulation comparison with the traditional engineering tuning PID controller, it is found that when the simulation process is t = 2000 s, the step disturbance with amplitude of 0.1 is added to the system input, and there will be slight disturbance in the combustion process. Through fuzzy PID and strong robustness support, the modeling error of the monitoring system model can be controlled between 10%∼25%, which proves that the nonlinear optimized PID has strong anti-interference and can meet the process requirements of the system.

An in situ exploratory analysis of diesel cars' emission: way forward on policy evaluation.

Keeping in view the significant number of diesel-driven passenger cars in the existing light motor vehicle fleet in Delhi, India, a case study on smoke emission measurement from 460 number of such cars was conducted. Smoke exhaust data was collected from the diesel cars while the vehicles presented themselves for periodic renewal of pollution under control (PUC) certification at authorized emission testing centers across Delhi, India. Along with the smoke emission, various vehicle- and engine-related aspects, supposed to affect tailpipe smoke emission, were also recorded aiming at data analysis for two datasets, namely whole and top 5 makes. The smoke density under no-loading condition in the free acceleration test mode was measured. The study reported a strong correlation between vehicle parameters, such as age, mileage, maintenance category, emission norm, and engine aspiration; and the smoke emission (R2 values for vehicle age and mileage vs. smoke emission for whole dataset = 0.872 and 0.873, respectively). Top 5 make-wise correlations fared even better (R2 for age and mileage vs. emission in the range of 0.85-0.92 and 0.86-0.93, respectively). Further, the predictive emission equations using best-fit trendlines were also developed for both datasets. Such equations may be used by the car manufacturers to adopt a suitable strategy for tuning of engine or vehicle as such, to retain their cars in the longer state of compliance to the extant emission norms. Further, the study recommends to include vehicle mileage as an important factor in upgrading the existing inspection and maintenance programs, especially in the developing countries.

Defect engineering tuning electron structure of biphasic tungsten-based chalcogenide heterostructure improves its catalytic activity for hydrogen evolution and triiodide reduction

The design and exploration of high-efficiency and low-cost electrode catalysts are of great significance to the development of novel energy conversion technologies. In this work, metal and nonmetal heteroatoms co-doped biphasic tungsten-based chalcogenide heterostructured catalyst (Co-WS2/P-WO2.9) with rich defects is successfully synthesized by a vulcanization technique. The electrocatalytic performance of WS2/WO3 in the hydrogen evolution reaction (HER) and triiodide reduction reaction is significantly enhanced by modifying and optimizing its electronic structure through a defect engineering strategy. As an electrocatalyst for HER, the optimized Co-WS2/P-WO2.9 exhibits a low overpotential at 10 mA cm−2 of 146 and 120 mV with small Tafel slopes of 86 and 74 mV dec−1 in alkaline and acidic electrolyte, respectively. In addition, a Co-WS2/P-WO2.9 assembled solar cell yields a short circuit current density of 15.85 mA cm−2, an open-circuit voltage of 0.74 V, a fill factor of 0.66, and a competitive power conversion efficiency (7.83%), which is comparable or higher than conventional Pt-based solar cell (16.02 mA cm−2, 0.70 V, 0.63, 7.14%). The formation of a heterostructure in Co-WS2/P-WO2.9 leads to the presence of a built-in electric field in the interfacial region between Co-WS2 and P-WO2.9, which leads to an increased open-circuit voltage from 0.70 V for Pt to 0.74 V for Co-WS2/P-WO2.9. This work can provide a technical support for developing high-performance heterostructured catalysts, which open up a way for improving catalytic performance of heterostructured catalysts in the field of electrocatalysis.

Application and Development of Selective Catalytic Reduction Technology for Marine Low-Speed Diesel Engine: Trade-Off among High Sulfur Fuel, High Thermal Efficiency, and Low Pollution Emission

In recent years, the International Maritime Organization (IMO), Europe, and the United States and other countries have set up different emission control areas (ECA) for ship exhaust pollutants to enforce more stringent pollutant emission regulations. In order to meet the current IMO Tier III emission regulations, an after-treatment device must be installed in the exhaust system of the ship power plant to reduce the ship NOx emissions. At present, selective catalytic reduction technology (SCR) is one of the main technical routes to resolve excess NOx emissions of marine diesel engines, and is the only NOx emission reduction technology recognized by the IMO that can be used for various ship engines. Compared with the conventional low-pressure SCR system, the high-pressure SCR system can be applied to low-speed marine diesel engines that burn inferior fuels, but its working conditions are relatively harsh, and it can be susceptible to operational problems such as sulfuric acid corrosion, salt blockage, and switching delay during the actual ship tests and ship applications. Therefore, it is necessary to improve the design method and matching strategy of the high-pressure SCR system to achieve a more efficient and reliable operation. This article summarizes the technical characteristics and application problems of marine diesel engine SCR systems in detail, tracks the development trend of the catalytic reaction mechanism, engine tuning, and control strategy under high sulfur exhaust gas conditions. Results showed that low temperature is an important reason for the formation of ammonium nitrate, ammonium sulfate, and other deposits. Additionally, the formed deposits will directly affect the working performance of the SCR systems. The development of SCR technology for marine low-speed engines should be the compromise solution under the requirements of high sulfur fuel, high thermal efficiency, and low pollution emissions. Under the dual restrictions of high sulfur fuel and low exhaust temperature, the low-speed diesel engine SCR systems will inevitably sacrifice part of the engine economy to obtain higher denitrification efficiency and operational reliability.

Electric field and strain engineering tuning Rashba spin splitting in quasi-one-dimensional organic-inorganic hybrid perovskites (MV)AI3Cl2 (MV = methylviologen, A = Bi, Sb).

We systematically study the Rashba spin texture of lead-free quasi-one-dimensional organic-inorganic hybrid perovskites (OIHP), (MV)AI3Cl2 (MV = methylviologen, A = Bi, Sb) with first-principles calculations. The kx-ky plane Rashba spin splitting was found to depend on the composition of Bi (Sb) and I atoms at band edges. Importantly, increasing ferroelectric polarization and the stretch along the z-direction can effectively enhance the amplitude of the Rashba spin splitting. This work provides an avenue for electric field and strain-controlled spin splitting and highlights the potential of quasi-one-dimensional OIHP for further applications in spin field effect transistors and photovoltaic cells.

Enhancing thermoelectric performance of K-doped polycrystalline SnSe through band engineering tuning and hydrogen reduction

High-efficient and environment-friendly thermoelectric materials have attracted much attention. The single crystal tin selenide (SnSe) has a record high thermoelectric figure of merit (ZT) of 2.6 at ~800 K. Polycrystalline SnSe has better mechanical-strength but inferior ZT values than the single crystal, attribute to the paradoxically higher thermal conductivity (κ). In this work, we synthesized KxSn1−xSe (x = 0, 0.01, 0.02, 0.03 and 0.04) by doping K2CO3. A large number of point defects and dislocations generated with CO2 volatilization, which possibly reduces κ. Based on this process, the KxSn1−xSe powders were followed by the hydrogen reduction with 4% H2 − 96% Ar atmosphere to reduce tin oxide and potassium oxide which have high κ. These strategies lead to an ultra-low κ 0.32 Wm−1K−1 in K0.03Sn0.97Se at 798 K. The effects of K doping on electronic transport performance of SnSe were studied by density functional theory calculation and experimental measurement. Doing K can narrow the band gap, increase hole concentration and enhance the electrical conductivity (σ) of SnSe. At 298 K, the σ of KxSn1−xSe increased by more than 2.5 times compared with the pristine SnSe. In high temperature region (623 K< T < 823 K), the σ is mainly affected by thermal excitation. High doping level of K (x = 0.03 and 0.04) suppresses the thermal excitation and limits the maximum of ZT. As the result, A high ZT of 1.06 is obtained at 798 K from K0.01Sn0.99Se perpendicular to the pressing direction, which is 103.8% larger than that of pristine SnSe. In addition, the hot-pressing polycrystalline KxSn1−xSe remains obvious lamellar morphology and show anisotropy. The σ and κ of KxSn1−xSe samples perpendicular to the pressure direction are much higher than those of the samples parallel to the pressure direction. This anisotropy decreases with the increasing K content.

The 3D porous “celosia” heterogeneous interface engineering of layered double hydroxide and P-doped molybdenum oxide on MXene promotes overall water-splitting

Exploiting efficient and economical electrocatalysts is indispensable for promoting the sluggish kinetics of overall water-splitting. Herein, we ingeniously designed a simple one-pot hydrothermal method to construct a 3D porous “celosia-like” heterogeneous framework of FeCo-layered double hydroxide (FeCo-LDH) and P-doped molybdenum oxide (P-MoO3) grown in-situ on MXene-modified nickel foam substrate (denoted as P-MoO3 FCL MXene/NF), with high conductivity, highly hydrophilic properties, and favorable kinetics. Density functional theory calculations (DFT) demonstrate that the electronic engineering tuning of electron dissipation and aggregation at the heterogeneous interface of P-MoO3 and FeCo-LDH optimizes the electron transfer rate of the active site and the d-band center near the Fermi level, thereby reducing the adsorption energy of H and O reaction intermediates (H*, OH*, OOH*) and improves the intrinsic catalytic activity. As expected, benefiting from the strong chemical and electron synergistic effect between heterogeneous structures, the synthesized P-MoO3 FCL MXene/NF heterogeneous framework exhibits excellent activity for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) with a low overpotential of 179 mV and 118 mV at 10 mA cm−2, respectively, and Faraday efficiency of up to 96 %. Significantly, the overpotential of 1.53 V is enough to drive a current density of 10 mA cm−2 in a two-electrode configuration which is greatly superior to other bifunctional electrocatalysts.

Realizing high thermoelectric performance in hot-pressed polycrystalline AlxSn1-xSe through band engineering tuning

SnSe-based thermoelectric materials are being explored since they have potential high thermoelectric figure of merit. We synthesized polycrystalline AlxSn1-xSe (x = 0.01, 0.02, 0.03 and 0.04) by hot-pressing method, and combined theoretical estimation with experimental measurement to investigate the influence of Al doping on thermoelectric properties of SnSe. It was found that dopant Al can effectively adjust the band structure of SnSe by introducing intermediate band. Al doping with low content (x = 0.01 and 0.02) can introduce a single intermediate band close to the valence band maximum or conduction band minimum, achieving band engineering optimization. In high temperature region (498 K < T < 823 K), the electronic transport properties significantly enhance with thermal excitation. The lattice thermal conductivity reduces with the Al atomic point defect scattering, leading to a low thermal conductivity of 0.47 W m−1K−1 in Al0.04Sn0.96Se at 823 K. As a result, a high ZT of 0.84 at 823 K is obtained from the Al0.04Sn0.96Se perpendicular to the pressing direction, which is 58.5% larger than that of SnSe. In addition, dopant Al can adjust the anisotropy of polycrystalline SnSe. The anisotropy of electronic properties are enhanced with low doping level (x = 0.01, 0.02) and suppressed with high doping level (x = 0.03, 0.04).

International Conference on Advanced and Competitive Manufacturing Technologies milling tool wear prediction using unsupervised machine learning

Degraded or defect machine components and consumables negatively impact manufacturing quality and productivity. Diagnosing and predicting the wear or degradation status of critical machine components or parts are therefore of general interest. To tackle this challenge, data-driven approaches based on supervised machine learning principles have demonstrated promising results. However, supervised learning models capable of degradation identification require large quantities of data. In practice, run-to-failure data in large amounts is usually not available and expensive to obtain. To overcome this issue, this study proposes an unsupervised learning approach for degradation prognostics of machine tool components and consumables. It uses time series of multi-sensor signal data, which are transformed into a feature representation. The features consist of various characterizations of the time series, allowing to make different signal measurements comparable, and cluster them according to their feature values. The herewith obtained density-based clustering model is used to diagnose and predict the degradation states of components and parts in unknown conditions. The novelty in the proposed approach lies within the identification of continuous component and part degradation states based on unsupervised learning principles. The proposal is verified and demonstrated on an exemplary data set containing a small sample of run-to-failure multi-sensor signals of milling inserts and their corresponding wear state. By the application of the proposed procedure on the exemplary data set, we demonstrate that an unsupervised clustering approach is capable of separating wear data such that meaningful and accurate estimations of the part condition are possible. The advantages are its ability to cope with scarce data sets, its limited engineering and hyperparameter tuning effort, and its straightforward implementation to a multitude of degradation and wear diagnostics scenarios.

Defect engineering tuning of MnO2 nanorods bifunctional cathode for flexible asymmetric supercapacitors and microbial fuel cells

An effective surface and structural modulation strategy is developed to greatly boost the electron transfer rate, active sites as well as cycle stability of MnO2 nanorods by introducing native oxygen vacancies. Consequently, the as-prepared material exhibits exceptional performances as a dual function positive electrode for flexible asymmetric supercapacitors (ASCs) and microbial fuel cells (MFCs). Benefiting from its higher surface area, increased active sites and much better reaction kinetics, the maximum energy density of ASCs device reaches 56.04 Wh kg−1, and the highest power density is 1639 mW m−2 for the MFCs device. Most importantly, a self-powered system has been built by integrating the flexible ASCs and MFCs, which be able to achieve chemical energy conversion and energy storage.

Engine knock detection for a multifuel engine using engine block vibration with statistical approach

Engine knock is an obstacle for maximizing CNG fuel utilization on a Diesel-CNG Dual Fuel engine. Prolong experience of this phenomenon may lead to severe engine damage. The low intensity of this phenomenon is difficult to recognize due to other noises from the engine. Thus, improper engine tuning techniques may make this phenomenon unnoticeable until the engine damages. Knock phenomena on such engines may not be detected in the combustion analysis graph. Its random occurrence in consecutive engine cycles makes it difficult to be seen using visual data. This knowledge gap, if closed, can lead to an opportunity for knock avoidance on the multifuel engine. This work proposed a method to quantify the knock occurrence based on engine block vibration using a single piezoelectric knock sensor. The knock occurrence was detected by comparing the calculated knock index with the knock threshold, determined using a statistical three-sigma rule analysis. This method can index the knock intensity, detect the engine knock occurrence, and visualize the knock phenomenon.•This paper describes an alternative engine knock detection technique based on engine block vibration.•This method proposes the knock threshold determination based on statistical three-sigma rule analysis.•This method is capable of visualizing the knock phenomenon in consecutive and at each engine cycle.

The Effect of separated Expansion Chamber Parameters on Exhaust Pressure Oscillations in Single Cylinder Motorcycle Engine

Abstract This paper investigates the effect of separated exhaust expansion chamber parameters on pressure oscillations in spark-ignited internal combustion (IC) gasoline engines. It is known that exhaust expansion chambers are becoming increasingly more popular among both – original equipment (OE) and aftermarket equipment (AE) exhaust system manufacturers for performance-oriented motorcycles equipped with mainly single cylinder engines, but the companies are reluctant to reveal any detailed principles of operation of the mentioned expansion chambers. The subject of this research is the type of expansion chamber (separate) as used on performance-oriented motorcycles, particularly its’ effect on exhaust pressure pulsations as different chamber volumes, locations and passage sizes are tested. Time-dependent computational fluid dynamics (CFD) analysis was carried out in Solidworks Flow Simulation environment on a simplified exhaust header pipe model imitating engine operation at full load and steady speed. Honda CRF450R motorcycle engine was used as the example and fully defined using a 1D engine performance calculator software to determine the combustion chamber pressure and exhaust valve lift at any given crankshaft position. Volume flow rate of exhaust gasses at the header pipe inlet was calculated based on engine parameters and operating speed. The average pressure values with respect to physical time were measured and graphed across the header pipe inlet cross-section. Eight different header pipe and exhaust expansion chamber combinations were modelled, tested, and results compared at low, medium and high engine speeds. It was found that the presence of exhaust expansion chamber tends to dampen the amplitude and decrease the frequency of pressure oscillations generated at the opening of the exhaust valve(s). Observations show that the addition of an expansion chamber as per design of performance-oriented motorcycles helps to decrease the negative effect of engine tuning while also dampening the positive effect.