Analysis and Development of Restrictor for Parallel Twin Engine in FSAE Cars

Abstract Axial flow fans (AFF) are extensively used in various industrial sectors, usually with flows of low resistance and high mass flow rates. The blades, the hub and the shroud are the three major parts of an AFF. Various kinds of optimisation can be implemented to improve the performance of an AFF. The most common type is found to be geometric optimisation including variation in number of blades, modification in hub and shroud radius, change in angle of attack and blade twist, etc. After validation of simulation model and carrying out a grid independence test, parametric analysis was done on an 11-bladed AFF with a shroud of uniform radius using ANSYS Fluent. The rotational speed of the fan and the velocity at fan inlet were the primary variables of the study. The variation in outlet mass flow rate and total pressure was studied for both compressible and incompressible ambient flows. Relation of mass flow rate and total pressure with inlet velocity is observed to be linear and exponential respectively. On the other hand, mass flow rate and total pressure have nearly linear relationship with rotational speed. A comparison of several different axial flow tracks with the baseline case fills one of the research gaps.

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Comparison of Swing and Tilting Check Valves Flowing Compressible Fluids

Micromachines ◽

10.3390/mi11080758 ◽

2020 ◽

Vol 11 (8) ◽

pp. 758

Author(s):

Zhi-xin Gao ◽

Ping Liu ◽

Yang Yue ◽

Jun-ye Li ◽

Hui Wu

Keyword(s):

Mach Number ◽

Mass Flow Rate ◽

Mass Flow ◽

Flow Rate ◽

Check Valve ◽

Small Mass ◽

Working Fluid ◽

Valve Disc ◽

Valve Opening ◽

The Difference

Although check valves have attracted a lot of attention, work has rarely been completed done when there is a compressible working fluid. In this paper, the swing check valve and the tilting check valve flowing high-temperature compressible water vapor are compared. The maximum Mach number under small valve openings, the dynamic opening time, and the hydrodynamic moment acting on the valve disc are chosen to evaluate the difference between the two types of check valves. Results show that the maximum Mach number increases with the decrease in the valve opening and the increase in the mass flow rate, and the Mach number and the pressure difference in the tilting check valve are higher. In the swing check valve, the hydrodynamic moment is higher and the valve opening time is shorter. Furthermore, the valve disc is more stable for the swing check valve, and there is a periodical oscillation of the valve disc in the tilting check valve under a small mass flow rate.

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Design and Optimization of the Restrictor of a Race Car

Volume 7B: Fluids Engineering Systems and Technologies ◽

10.1115/imece2015-52940 ◽

2015 ◽

Author(s):

Prithvi Raj Kokkula ◽

Shashank Bhojappa ◽

Selin Arslan ◽

Badih A. Jawad

Keyword(s):

Fluid Dynamics ◽

Pressure Drop ◽

Mass Flow Rate ◽

Mass Flow ◽

Flow Rate ◽

Air Flow ◽

Intake Manifold ◽

Maximum Pressure ◽

Cross Sectional ◽

Formula Sae

Formula SAE is a student competition organized by SAE International. The team of students design, manufacture and race a car. Restrictions are imposed by the Formula SAE rules committee to restrict the air flow into the intake manifold by putting a single restrictor of 20 mm. This rule limits the maximum engine power by reducing the mass flow rate flowing to the engine. The pull is greater at higher rpms and the pressure created inside the cylinder is low. As the diameter of the flow path is reduced, the cross sectional area for flow reduces. For cars running at low rpm when the engine requires less air, the reduction in area is compensated by accelerated flow of air through the restrictor. Since this is for racing purpose cars here are designed to run at very high rpms where the flow at the throat section reach sonic velocities. Due to these restrictions the teams are challenged to come up with improved restrictor designs that allow maximum pressure drop across the restrictor’s inlet and outlet. The design considered for optimizing a flow restrictor is a venturi type having 20 mm restriction between the inlet and the outlet complying with the rules set by Formula SAE committee. The primary objective of this work is to optimize the flow restriction device that achieves maximum mass flow and minimum pull from the engine. This implies the pressure difference created due to the cylinder pressure and the atmospheric pressure at the inlet should be minimum. An optimum flow restrictor is designed by conducting analysis on various converging and diverging angles and coming up with an optimum value. Venturi type is a tubular pipe with varying diameter along its length, through which the fluid flows. Law of governing fluid dynamics states that the “Velocity of the fluid increases as it passes through the constriction to satisfy the principle of continuity”. An equation can be derived from the combination of Bernoulli’s equation and Continuity equation for the pressure drop due to venturi effect. [1]. A Computational Fluid Dynamics (CFD) tool is used to calculate the minimum pressure drop across the restrictor by running a series of analysis on various converging and diverging angles and calculating the pressure drop. As a result, an optimum air flow restrictor is achieved that maximizes the mass flow rate and minimizes the engine pull.

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Three-Dimensional Fluid Dynamics and Radiative Heat Transfer Modeling of a Small Particle Solar Receiver

ASME 2013 7th International Conference on Energy Sustainability ◽

10.1115/es2013-18149 ◽

2013 ◽

Author(s):

Pablo Fernández del Campo ◽

Fletcher Miller ◽

Adam Crocker

Keyword(s):

Heat Transfer ◽

Mass Flow Rate ◽

Mass Flow ◽

Flow Rate ◽

Small Particle ◽

Radiative Heat ◽

Three Dimensional ◽

Solar Irradiation ◽

Ansys Fluent ◽

Solar Receiver

We present an investigation of the effects of the solar irradiation and mass flow conditions on the behavior of a Small Particle Solar Receiver employing our new, three-dimensional coupled fluid flow and radiative heat transfer model. This research expands on previous work conducted by our group and utilizes improved software with a set of new features that allows performing more flexible simulations and obtaining more accurate results. For the first time, it is possible not only to accurately predict the overall efficiency and the wall temperature distribution of the solar receiver, but also to determine the effect on the receiver of the window, the outlet tube, real solar irradiation from a heliostat field, non-cylindrical geometries and 3-D effects. This way, a much better understanding of the receiver’s capabilities is obtained. While the previous models were useful to observe simple trends, this new software is flexible and accurate enough to eventually act as a design and optimization tool for the actual receiver. The solution procedure relies on the coupling of the CFD package ANSYS Fluent to our in-house Monte Carlo Ray Trace (MCRT) software. On the one hand, ANSYS Fluent is utilized as the mass-, momentum- and energy-equation solver and requires the divergence of the radiative heat flux, which constitutes a source term of the energy equation. On the other hand, the MCRT software calculates the radiation heat transfer in the solar receiver and needs the temperature field to do so. By virtue of the coupled nature of the problem, both codes should provide feed-back to each other and iterate until convergence. The coupling between ANSYS Fluent and our in-house MCRT code is done via User-Defined Functions. After developing the mathematical model, setting up and validating the software, and optimizing the coupled solution procedure, the receiver has been simulated under fifteen different solar irradiation and mass flow rate cross combinations. Among other results, the behavior of the receiver at different times of the day and the optimum mass flow rate as a function of the solar thermal input are presented. On an average day, the thermal efficiency of the receiver is found to be over 89% and the outlet temperature over 1250 K at all times from 7:30 AM to 4:00 PM (Albuquerque, NM) by properly adapting the mass flow rate. The origin of the losses and how to improve the efficiency of the Small Particle Solar Receiver are discussed as well.

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Experimental Investigation of Flow Instability in a Supersonic Inlet

ASME 2010 10th Biennial Conference on Engineering Systems Design and Analysis, Volume 3 ◽

10.1115/esda2010-24858 ◽

2010 ◽

Cited By ~ 2

Author(s):

Mohammad Reza Soltani ◽

Mohammad Farahani

Keyword(s):

Mach Number ◽

Mass Flow Rate ◽

Mass Flow ◽

Flow Rate ◽

Flow Instability ◽

Wind Tunnel Test ◽

External Flow ◽

Pressure Data ◽

Supersonic Inlet ◽

Shock Oscillation

An extensive wind tunnel test series were conducted on an axisymmetric supersonic inlet. The model was tested at Mach numbers from 1.8 to 2.2 and at different values of mass flow rate. Shadowgraph flow visualization was used to capture the external shock structure in front of the inlet. The goal of this study is to find out the general characteristics of the inlet buzz. Frequencies of the buzz have been achieved from the analysis of the pressure data as well as the shadowgraph pictures. The amplitude of the shock waves motion has been measured from the visualization pictures too. In the some large value of mass flow rate, the frequency of shock oscillation increased versus Mach number. Also in each Mach number due to the mass flow rate decrement, the buzz frequency decreases and its amplitude increases conversely. Also buzz instability affects the external flow by the same frequency of the internal one.

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Performance study of an inlet in supersonic flow

Proceedings of the Institution of Mechanical Engineers Part G Journal of Aerospace Engineering ◽

10.1177/0954410011426672 ◽

2012 ◽

Vol 227 (1) ◽

pp. 159-174 ◽

Cited By ~ 7

Author(s):

Mohammad R Soltani ◽

Mohammad Farahani

Keyword(s):

Mach Number ◽

Mass Flow Rate ◽

Mass Flow ◽

Flow Rate ◽

Free Stream ◽

Characteristic Curve ◽

Pressure Recovery ◽

Internal Boundary ◽

Performance Study ◽

Free Stream Mach Number

The performance characteristics of an axisymmetric inlet at its design and off-design operational conditions are experimentally investigated. The model is tested for wide ranges of free stream Mach numbers, M∞ = 1.5–2.5, and mass flow rates. For each test, the pressure recovery, the mass flow passing through the inlet and the pressure distribution over the spike and the cowl are measured. In addition, the shock wave formed in front of the inlet is visualized. The characteristic curve of the inlet is then obtained for each free stream Mach number. As the Mach number is increased, the pressure recovery is reduced, but the maximum value of the mass flow rate grows up. Variations of the mass flow affect the surface pressure over both the front portion of the cowl and the entire surface of the spike. Further, it has changed both pressure and Mach number at the end of the diffuser, which would consequently affect the performance of the propulsion system. In addition, contrary to the internal boundary layer, the external one far from the cowl lip has been found to be almost independent of the inlet mass flow rate for a constant free stream Mach number.

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Design of an Optimized Inlet Shroud for a Flanged Diffuser

10.31224/osf.io/2qb6r ◽

2019 ◽

Author(s):

Dhruv Suri

Keyword(s):

Numerical Simulation ◽

Wind Turbine ◽

Mass Flow Rate ◽

Mass Flow ◽

Flow Rate ◽

Static Pressure ◽

Horizontal Axis Wind Turbine ◽

Ansys Fluent ◽

Modelling Techniques ◽

Flow Through

Numerical simulation using commercial CFD package ANSYS Fluent ® is carried out for a horizontal axis wind turbine with a flanged diffuser. An optimized inlet shape that further accelerates the flow through the diffuser has been proposed and evaluated. The principle behind the increase in mass flow rate due to the shape of the inlet shroud has been discussed, with emphasis on the modelling techniques presented. The low static pressure aft of the flange at the exit periphery induces a greater mass flow through the diffuser, thereby resulting in a higher capacity factor of the enclosed wind turbine. A comparison between different inlet shroud configurations has also been presented.

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Performance Trends For Aerospikes & Supersonic Nozzles With Center-Bodies

10.32920/ryerson.14655753 ◽

2021 ◽

Author(s):

Bassel El-Dahr

Keyword(s):

Mass Flow Rate ◽

Mass Flow ◽

Flow Rate ◽

Specific Impulse ◽

Working Fluid ◽

Base Case ◽

Conical Nozzle ◽

Ansys Fluent ◽

Supersonic Nozzles ◽

Calculated Mass

The aim of this report is to examine performance trends for Aerospikes and Supersonic nozzles with center – bodies. The initial case that was tested is a convergent – divergent conical nozzle with a geometry and inlet flow conditions obtained from a NASA technical note. The technical note mentions that air was used as the working fluid for the nozzle. This case served as the base case for comparison with the performance of later nozzle designs. Nozzle flow for all the cases that were tested was simulated using ANSYS Fluent, for ambient conditions at 20km standard atmosphere. The convergent – divergent conical nozzle has the following calculated performance parameters using results from ANSYS Fluent: mass flow rate of 9.660 kg/s, axial Thrust of 10,583.5 N, and a specific impulse of 111.7s. All of the Supersonic nozzles with center – bodies have calculated specific impulse values lower than 111.7s by 0.4 – 1.6s, for approximately the same calculated mass flow rates as the base case. Adding a center – body to the original conical nozzle, was simply detrimental to performance. With regards to the Aerospike nozzles, 18 of them were tested. Aerospike 18 has the highest calculated specific impulse, at 115.3s for a calculated mass flow rate of 9.671kg/s. Aerospike 13 came in second at 114.6s, for a calculated mass flow rate of 9.676 kg/s. Several of the Aerospike designs did not out-perform the base case in terms of specific impulse. For those Aerospikes, the convergent – divergent section had a significantly lower thrust than the base case and the center – body was not able to over-compensate for the lower thrust. This report also looks at trends in thrust contribution by the convergent – divergent sections and center – bodies of Aerospikes at different nozzle geometries. The working fluid for all the cases tested in ANSYS Fluent including the base case, is air at a ratio of specific heats equal to 1.4.

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Design and aerodynamic performance analysis of a variable geometry axisymmetric inlet for TBCC

International Journal of Turbo and Jet Engines ◽

10.1515/tjeng-2020-0030 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Yunfei Wang ◽

Huacheng Yuan ◽

Jinsheng Zhang ◽

Zhenggui Zhou

Keyword(s):

Mach Number ◽

Performance Analysis ◽

Mass Flow Rate ◽

Mass Flow ◽

Flow Rate ◽

Design Method ◽

Aerodynamic Performance ◽

Combined Cycle ◽

Variable Geometry

Abstract Design and aerodynamic performance analysis of a variable geometry axisymmetric inlet was carried out for tandem scheme turbine-based combined cycle (TBCC) propulsion system. The operation Mach number of the inlet was between 0 and 4. The design point was chosen as Mach number 4.0 in this paper. The determination of external and internal compression and the design method of annular to circle diffuser were illustrated. The inlet was unstart under Ma 3.0 without adjustment. Then, a variable scheme was designed to ensure self-start of the inlet and match the requirement of mass flow rate during the whole flight envelope. And four supports were used to fix the spike. According to the 3D numerical simulations, the total pressure recovery was 0.52 at Ma 4.0 at critical condition and the mass flow rate was consistent with the requirement at different flight Mach number.

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Performance Trends For Aerospikes & Supersonic Nozzles With Center-Bodies

10.32920/ryerson.14655753.v1 ◽

2021 ◽

Author(s):

Bassel El-Dahr

Keyword(s):

Mass Flow Rate ◽

Mass Flow ◽

Flow Rate ◽

Specific Impulse ◽

Working Fluid ◽

Base Case ◽

Conical Nozzle ◽

Ansys Fluent ◽

Supersonic Nozzles ◽

Calculated Mass

The aim of this report is to examine performance trends for Aerospikes and Supersonic nozzles with center – bodies. The initial case that was tested is a convergent – divergent conical nozzle with a geometry and inlet flow conditions obtained from a NASA technical note. The technical note mentions that air was used as the working fluid for the nozzle. This case served as the base case for comparison with the performance of later nozzle designs. Nozzle flow for all the cases that were tested was simulated using ANSYS Fluent, for ambient conditions at 20km standard atmosphere. The convergent – divergent conical nozzle has the following calculated performance parameters using results from ANSYS Fluent: mass flow rate of 9.660 kg/s, axial Thrust of 10,583.5 N, and a specific impulse of 111.7s. All of the Supersonic nozzles with center – bodies have calculated specific impulse values lower than 111.7s by 0.4 – 1.6s, for approximately the same calculated mass flow rates as the base case. Adding a center – body to the original conical nozzle, was simply detrimental to performance. With regards to the Aerospike nozzles, 18 of them were tested. Aerospike 18 has the highest calculated specific impulse, at 115.3s for a calculated mass flow rate of 9.671kg/s. Aerospike 13 came in second at 114.6s, for a calculated mass flow rate of 9.676 kg/s. Several of the Aerospike designs did not out-perform the base case in terms of specific impulse. For those Aerospikes, the convergent – divergent section had a significantly lower thrust than the base case and the center – body was not able to over-compensate for the lower thrust. This report also looks at trends in thrust contribution by the convergent – divergent sections and center – bodies of Aerospikes at different nozzle geometries. The working fluid for all the cases tested in ANSYS Fluent including the base case, is air at a ratio of specific heats equal to 1.4.

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