scholarly journals The experimental study on the performances of the thermoelectric generator unit affected by heat rate of exhaust system

2021 ◽  
Vol 3 (SI2) ◽  
pp. SI24-SI36
Author(s):  
THONG DUC HONG ◽  
QUAN PHAN THIEN NGHIEM ◽  
TINH VAN MAI
Keyword(s):  
Heat Loss ◽  
Output Power ◽  
High Speed ◽  
Thermoelectric Generator ◽  
Exhaust System ◽  
Heat Rate ◽  
Vehicle Speed ◽  
Insulation Material ◽  
Generator Unit ◽  
The Difference

This study examines the effect of heat rate transferring from the exhaust system of motorcycle to the environment on the performance of the Thermoelectric Generator Unit (TGU). This heat rate is changed by attaching thermal insulation material on the outside of the exhaust system and changing the heat absorbing area of the TGU. The TGU consists of 8 thermoelectric generator modules and collects heat energy from the exhaust to produce electricity. It is attached on the custom muffler of the Suzuki Sapphire 125 and tested in the speed range from 20km/h to 50km/h. The results show that this heat rate affects both the temperature and output power generated by the TGU. The reduction of this heat rate reduces the cool side temperature by limiting the warming effect of cooling air and raise the hot side temperature of the TGU by decreasing heat loss. These two effects lead to the increase of the temperature difference between both sides of the TGU and therefore the output power increases. The difference in output power between test cases can reach up to 54%. Moreover, the heat loss at exhaust tube affects both temperature and output power of TGU from low to mid vehicle speed. However, at high speed, this heat loss at the exhaust tube does not considerably affect the output power of the TGU. To summarize, by reducing the heat rate between exhaust system and environment, the TGU can reach its stable working condition faster and produces more output power. Nonetheless, reducing this heat rate too much may lead to the excess of the hot side temperature of TGU, therefore damaging the thermoelectric generator modules and reducing the conversion efficiency of the TGU.

A Prototype Steering Weave Stabilizer for Automobiles

1991 ◽  
Vol 113 (1) ◽  
pp. 138-142 ◽  
Author(s):  
J. C. Whitehead
Keyword(s):  
High Speed ◽  
Steering System ◽  
Lateral Acceleration ◽  
Steering Wheel ◽  
Phase Lag ◽  
Vehicle Speed ◽  
Control Torque ◽  
Concentrated Mass ◽  
Wheel Rim ◽  
The Difference

A prototype high-speed steering stabilizer for automobiles applies transient steering torques so that the sum of natural steering restoring torque and the control torque is more nearly in phase with steer angle than the natural restoring torque alone. The resulting reduction in the phase lag from steer angle to restoring torque mitigates the steering weave mode. Since steering restoring torque is nearly proportional to vehicle lateral acceleration, weave controller circuitry could subtract instantaneous lateral acceleration from expected steady-state lateral acceleration calculated from steer angle and vehicle speed, and thence command a steering torque actuator depending on the difference signal. The prototype performs the same function using a concentrated mass on the lower steering wheel rim which is passively sensitive to both steer angle and lateral acceleration, thereby applying only transient steering torques in the desired manner at a vehicle speed of 30 m/s. The additional steering system inertia alone affects the weave mode, so a non-stabilizing configuration with the same mass distributed around the steering wheel rim is tested for direct comparison. The experimental data show a dramatic stabilization of weave for the configuration which applies control torque.

EXPERIMENTAL INVESTIGATION TO ENHANCE THE POWER GENERATION FOR THERMOELECTRIC GENERATOR UNIT

2019 ◽  
Vol 50 (5) ◽  
pp. 451-462
Author(s):  
Abhishek Khanchi ◽  
Mani Kanwar Singh ◽  
Harkirat Sandhu ◽  
Satbir Sehgal
Keyword(s):  
Power Generation ◽  
Experimental Investigation ◽  
Thermoelectric Generator ◽  
Generator Unit

Case study: Prediction and field tests of railway noise and effects of a low-height noise barrier

2020 ◽  
Vol 68 (4) ◽  
pp. 303-314
Author(s):  
Yuna Park ◽  
Hyo-In Koh ◽  
University of Science and Technology, Transpo ◽  
University of Science and Technology, Transpo ◽  
University of Science and Technology, Transpo ◽  
...  
Keyword(s):  
High Speed ◽  
Field Tests ◽  
Residential Areas ◽  
Railway Systems ◽  
Railway Noise ◽  
Sound Levels ◽  
Noise Barrier ◽  
The Difference ◽  
Reduction Effect ◽  
The Impact

Railway noise is calculated to predict the impact of new or reconstructed railway tracks on nearby residential areas. The results are used to prepare adequate counter- measures, and the calculation results are directly related to the cost of the action plans. The calculated values were used to produce noise maps for each area of inter- est. The Schall 03 2012 is one of the most frequently used methods for the production of noise maps. The latest version was released in 2012 and uses various input para- meters associated with the latest rail vehicles and track systems in Germany. This version has not been sufficiently used in South Korea, and there is a lack of standard guidelines and a precise manual for Korean railway systems. Thus, it is not clear what input parameters will match specific local cases. This study investigates the modeling procedure for Korean railway systems and the differences between calcu- lated railway sound levels and measured values obtained using the Schall 03 2012 model. Depending on the location of sound receivers, the difference between the cal- culated and measured values was within approximately 4 dB for various train types. In the case of high-speed trains, the value was approximately 7 dB. A noise-reducing measure was also modeled. The noise reduction effect of a low-height noise barrier system was predicted and evaluated for operating railway sites within the frame- work of a national research project in Korea. The comparison of calculated and measured values showed differences within 2.5 dB.

scholarly journals Prognostic Assessment of the Performance Parameters for the Industrial Diesel Engines Operated with Microalgae Oil

2021 ◽  
Vol 13 (11) ◽  
pp. 6482
Author(s):  
Sergejus Lebedevas ◽  
Laurencas Raslavičius
Keyword(s):  
Energy Efficiency ◽  
Diesel Engine ◽  
High Speed ◽  
Performance Parameters ◽  
Prognostic Assessment ◽  
High Speed Diesel ◽  
Microalgae Oil ◽  
The Difference ◽  
Smoke Opacity ◽  
Efficiency Indicators

A study conducted on the high-speed diesel engine (bore/stroke: 79.5/95.5 mm; 66 kW) running with microalgae oil (MAO100) and diesel fuel (D100) showed that, based on Wibe parameters (m and φz), the difference in numerical values of combustion characteristics was ~10% and, in turn, resulted in close energy efficiency indicators (ηi) for both fuels and the possibility to enhance the NOx-smoke opacity trade-off. A comparative analysis by mathematical modeling of energy and traction characteristics for the universal multi-purpose diesel engine CAT 3512B HB-SC (1200 kW, 1800 min−1) confirmed the earlier assumption: at the regimes of external speed characteristics, the difference in Pme and ηi for MAO100 and D100 did not exceeded 0.7–2.0% and 2–4%, respectively. With the refinement and development of the interim concept, the model led to the prognostic evaluation of the suitability of MAO100 as fuel for the FPT Industrial Cursor 13 engine (353 kW, 6-cylinders, common-rail) family. For the selected value of the indicated efficiency ηi = 0.48–0.49, two different combinations of φz and m parameters (φz = 60–70 degCA, m = 0.5 and φz = 60 degCA, m = 1) may be practically realized to achieve the desirable level of maximum combustion pressure Pmax = 130–150 bar (at α~2.0). When switching from diesel to MAO100, it is expected that the ηi will drop by 2–3%, however, an existing reserve in Pmax that comprises 5–7% will open up room for further optimization of energy efficiency and emission indicators.

scholarly journals CFD Simulation of a Hyperloop Capsule Inside a Low-Pressure Environment Using an Aerodynamic Compressor as Propulsion and Drag Reduction Method

2021 ◽  
Vol 11 (9) ◽  
pp. 3934
Author(s):  
Federico Lluesma-Rodríguez ◽  
Temoatzin González ◽  
Sergio Hoyas
Keyword(s):  
Shock Waves ◽  
Power Consumption ◽  
High Speed ◽  
Cfd Simulation ◽  
Aerodynamic Drag ◽  
Flow Behavior ◽  
Critical Conditions ◽  
Vehicle Speed ◽  
Blockage Ratio ◽  
The Cost

One of the most restrictive conditions in ground transportation at high speeds is aerodynamic drag. This is even more problematic when running inside a tunnel, where compressible phenomena such as wave propagation, shock waves, or flow blocking can happen. Considering Evacuated-Tube Trains (ETTs) or hyperloops, these effects appear during the whole route, as they always operate in a closed environment. Then, one of the concerns is the size of the tunnel, as it directly affects the cost of the infrastructure. When the tube size decreases with a constant section of the vehicle, the power consumption increases exponentially, as the Kantrowitz limit is surpassed. This can be mitigated when adding a compressor to the vehicle as a means of propulsion. The turbomachinery increases the pressure of part of the air faced by the vehicle, thus delaying the critical conditions on surrounding flow. With tunnels using a blockage ratio of 0.5 or higher, the reported reduction in the power consumption is 70%. Additionally, the induced pressure in front of the capsule became a negligible effect. The analysis of the flow shows that the compressor can remove the shock waves downstream and thus allows operation above the Kantrowitz limit. Actually, for a vehicle speed of 700 km/h, the case without a compressor reaches critical conditions at a blockage ratio of 0.18, which is a tunnel even smaller than those used for High-Speed Rails (0.23). When aerodynamic propulsion is used, sonic Mach numbers are reached above a blockage ratio of 0.5. A direct effect is that cases with turbomachinery can operate in tunnels with blockage ratios even 2.8 times higher than the non-compressor cases, enabling a considerable reduction in the size of the tunnel without affecting the performance. This work, after conducting bibliographic research, presents the geometry, mesh, and setup. Later, results for the flow without compressor are shown. Finally, it is discussed how the addition of the compressor improves the flow behavior and power consumption of the case.

A Fault Diagnosis Method for the Roller-Marks in Offset Printing Machine Based on Texture Recognition

2012 ◽  
Vol 262 ◽  
pp. 361-366
Author(s):  
Zhuo Fei Xu ◽  
Hai Yan Zhang ◽  
Ling Hui Ren
Keyword(s):  
Fault Diagnosis ◽  
High Speed ◽  
Solution Method ◽  
Offset Printing ◽  
Texture Recognition ◽  
Defect Image ◽  
Diagnosis Method ◽  
The Difference ◽  
Detecting Method ◽  
Printing Machine

Roller-mark is a common problem in offset printing and its solution method is important for printing. A new detecting method of texture analysis was given in this paper. In this study, printing image was acquired with high-speed CCD. Compared the difference between printing image and standard image, a defective image was obtained. Then the reason of roller-marks was given by the texture recognition of defect image. Finally, experiments were taken to prove the feasibility and effectiveness of this new method for the roller-marks diagnosis in the offset printing machine.

Experimental Investigation During Stall and Surge in a Transonic Fan Stage and Rotor-Only Configuration

2006 ◽  
Author(s):  
A. J. Gannon ◽  
G. V. Hobson ◽  
R. P. Shreeve ◽  
I. J. Villescas
Keyword(s):  
High Speed ◽  
Fast Response ◽  
Pressure Measurements ◽  
Post Processing ◽  
Transonic Compressor ◽  
Compressor Rotor ◽  
The Difference ◽  
Data Signal ◽  
Transonic Fan ◽  
Casing Pressure

High-speed pressure measurements of a transonic compressor rotor-stator stage and rotor-only configuration during stall and surge are presented. Rotational speed data showed the difference between the rotor-only case and rotor-stator stage. The rotor-only case stalled and remained stalled until the control throttle was opened. In the rotor-stator stage the compressor surged entering a cyclical stalling and then un-stalling pattern. An array of pressure probes was mounted in the case wall over the rotor for both configurations of the machine. The fast response probes were sampled at 196 608 Hz as the rotor was driven into stall. Inspection of the raw data signal allowed the size and speed of the stall cell during its growth to be investigated. Post-processing of the simultaneous signals of the casing pressure showed the development of the stall cell from the point of inception and allowed the structure of the stall cell to be viewed.

Numerical Simulation of Flowfield around High Speed Trains Passing by each other at the same Speed

2011 ◽  
Vol 97-98 ◽  
pp. 698-701
Author(s):  
Ming Lu Zhang ◽  
Yi Ren Yang ◽  
Li Lu ◽  
Chen Guang Fan
Keyword(s):  
Numerical Simulation ◽  
Wind Tunnel ◽  
Flow Field ◽  
Point Source ◽  
High Speed ◽  
Stokes Equations ◽  
Field Structure ◽  
Vehicle Speed ◽  
Mesh Method ◽  
High Speed Trains

Large eddy simulation (LES) was made to solve the flow around two simplified CRH2 high speed trains passing by each other at the same speed base on the finite volume method and dynamic layering mesh method and three dimensional incompressible Navier-Stokes equations. Wind tunnel experimental method of resting train with relative flowing air and dynamic mesh method of moving train were compared. The results of numerical simulation show that the flow field structure around train is completely different between wind tunnel experiment and factual running. Two opposite moving couple of point source and point sink constitute the whole flow field structure during the high speed trains passing by each other. All of streamlines originate from point source (nose) and finish with the closer point sink (tail). The flow field structure around train is similar with different vehicle speed.

Behavior of Unsteady Turbulent Starting Round Jets

2012 ◽  
Vol 134 (6) ◽  
Author(s):  
Neerav Abani ◽  
Jaal B. Ghandhi
Keyword(s):  
High Speed ◽  
Penetration Rate ◽  
Injection Rate ◽  
Injection Velocity ◽  
Time Varying ◽  
Velocity Change ◽  
Rate Of Penetration ◽  
Round Jets ◽  
The Difference ◽  
Sudden Decrease

Turbulent starting jets with time-varying injection velocities were investigated using high-speed schlieren imaging. Two solenoid-controlled injectors fed a common plenum upstream of an orifice; using different upstream pressures and actuation times, injection-rate profiles with a step increase or decrease in injection velocity were tested. The behavior of the jet was found to be different depending on the direction of the injection-velocity change. A step increase in injection velocity resulted in an increased rate of penetration relative to the steady-injection case, and a larger increase in injection velocity resulted in an earlier change in the tip-penetration rate. The step-increase data were found to be collapsed by scaling the time by a convective time scale based on the tip location at the time of the injection-velocity change and the difference in the injection velocities. A sudden decrease in injection velocity to zero was found to cause a deviation from the corresponding steady-pressure case at a time that was independent of the initial jet velocity, i.e., it was independent of the magnitude of the injection-velocity change. Two models for unsteady injection from the literature were tested and some deficiencies in the models were identified.

scholarly journals Composite Distribution Solution for Minimizing Heat Loss in a Pyrolysis Reactor

2011 ◽  
Vol 9 (1) ◽  
Author(s):  
Werner O. Filtvedt ◽  
Morten Melaaen ◽  
Arve Holt ◽  
Massoud Javidi ◽  
Birger Retterstøl Olaisen
Keyword(s):  
Heat Loss ◽  
Reaction Chamber ◽  
Inlet Temperature ◽  
Chemical Reactors ◽  
Normal Procedure ◽  
Pyrolysis Reactor ◽  
The Difference ◽  
Distribution Plate ◽  
Composite Distribution ◽  
Novel Design

The article presents a novel design for a distribution plate. The solution is suitable for a reactor vessel where a reactant gas needs to be maintained at a different temperature from the reaction chamber in order to avoid unwanted occurrences, such as clogging of the distribution plate. A normal procedure involves cooling of the distribution plate which is reported to either increase heat loss substantially or yield insufficient temperature in parts of the reaction chamber. The problem is especially important for reactors where the difference in reactant inlet temperature and desired reaction temperature is large. The investigated design utilized materials of very different thermal conductivity to only cool specific parts of the distribution arrangement and thereby minimize heat loss. Our system is a distribution plate for use in a fluidized bed reactor for silane pyrolysis. However, the solution is general and may be utilized in many types of vessels and chemical reactors.

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