Questions tagged [modeling]

Use this tag for questions about numerical or analytical modeling and simulation of engineered systems.

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6
votes
1answer
309 views

Questions regarding Cornering Stiffness for RC Car

I am a bachelor's level student tasked with modeling the vehicle dynamics of an RC Car that will be made to drive autonomously. I lack prior experience or particularly specific education with vehicle ...
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69 views

Solidworks Loft error (guide curve not intersecting with profiles)

I am trying to add 'finger grooves' to my model of a brake lever and want to use a loft to do so. I have created (to my knowledge) all required sketches for the loft but SW gives me an error when ...
4
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1answer
58 views

Holonomic constraint forces using Lagrange multipliers

Consider a multibody robotic system with Lagrangian $$ L =\frac{1}{2} \dot{q}^{T}M\dot{q} - V $$ and equations of motion of the form $$M(q)\ddot{q}+C(q,\dot{q})\dot{q}+A^{T}(q)\lambda+N(q)=0 $$ where ...
3
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0answers
26 views

Is there any formula to model the effective Young's Modulus of a fluid-filled spherical shell?

I am creating composites of a host epoxy and filler particles which are thin-walled fluid-filled shells. Using the Halpin-Tsai equations, for example, I can predict the bulk composite Young's modulus ...
3
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0answers
26 views

Problem in the inverse kinematic model of a car like vehicle?

I'm a electrical engineering student and i am building a simulation of a car like vehicle . As I understand it: The input for the forward kinematic model are the control variables and the output is ...
3
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0answers
107 views

How to obtain relative movement and rotation of bridge bearings?

In structural analysis of a bridge using whatever software, such as MIDAS or SAP 2000, it is easy to obtain the deformation of individual nodes. However, for bearings, what we want is the relative ...
3
votes
1answer
420 views

How to model Motor Windings in Solidworks?

I want to model a DC motor in order to eventually do some simulations (temperature/cooling related) and I'm wondering what is the best way to model the motor windings? I've seen a few video's on how ...
2
votes
1answer
66 views

How to design an enclosure around the load cell (Beam type)?

Hardware and Electronics Used: Arduino UNO, HX711 ADC Load cell amplifier, Load Cell (2Kg); Currently, I am working on a project which requires me to put load cell along with the other circuitry in an ...
2
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0answers
18 views

How are circular dependencies dealt with inside MBSE?

How are circular dependencies (best) managed inside of MBSE environments? Let's say I have two properties that are linked to each other / they are linked to properties that affect each other. How is ...
2
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0answers
23 views

Setup Invention Process in Engineering CAD Software

I need to develop a collapsible metal construction. I have a few specific prerequisites. Generally speaking, it will be something like a big construction toy, but not be a toy. It has the specific ...
2
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0answers
12 views

Increase in target emission rate (TER) when using a air source heat pump (ASHP) in standard assessment procedure (SAP) calculation

I am running a SAP calculation on a proposed building which will be utilising a 8.5 kW ASHP for space and water heating. I am also running a comparative analysis against a mains gas boiler to show the ...
2
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0answers
23 views

How does one calculate the principial component stresses in an ellipsoidal tank due to head pressure?

I have parameterized the following common bulkhead tank, which has cylindrical walls (easy enough) and ellipsoidal bulkheads. The upper tank is full of a fluid of density 800 kg/m^3 and the lower is ...
2
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0answers
19 views

Custom Models in Process Engineering

I'm using Aspen Custom Modeler to create a model to be used in Aspen Plus and Aspen Plus Dynamics, and I'm having trouble figuring out how to code the mass balance, energy balance, etc. I'm ...
2
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0answers
81 views

How to join two beams rigidly?

Hi I am making a beam model using Abaqus. There are two beams created. I wanted to join two beams rigidly in the connection to transfer moments between beams. However, I do not know what connector or ...
2
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0answers
82 views

What specific characteristic of proportional solenoid valves makes the flow to current behavior quadratic?

If experimental data is obtained from a proportional solenoid valve, specifically flow vs current (assuming inlet pressure is constant), the fit is nearly quadratic in nature. Andersen's Analysis and ...
2
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0answers
61 views

How can I model a plane's trajectory in a simple way?

I would like to model a plane trajectory, here are my assumptions and conclusions so far: Assumptions: we denote the plane's speed with $v(t)$, its trajectory $x(t)$, the total trajectory time will ...
2
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0answers
75 views

Inventor: How to replace static part with articulation?

I have downloaded the following part file of a servo motor as IGES from the vendor: I have then built an assembly that uses several of these motors, as well as a number of idlers/hubs, brackets, ...
2
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0answers
196 views

Modeling heat and mass transfer modes inside rapidly rotating cylinder

My question is about simultaneous heat and mass transfer in rotating cylinder system. System can be detailed as: A rotating cylinder contains wet porous substance in a lump shape. Air stream enters ...
2
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0answers
1k views

What data do I need to plot a BSFC map

I have an 4 stroke spark ignition engine simulator which takes user inputs and outputs performance data. I need rpm, torque and brake specific fuel consumption (bsfc) to plot the bsfc map. I am able ...
1
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0answers
36 views

Superimposing a Vector Field onto a Toroid in Matlab

I am a systems and control PhD student in Aerospace Engineering. Currently, I am trying to create a wind shear model of a toroidal thermal "bubble" in Matlab similar to the one in this paper (shown ...
1
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0answers
24 views

Slow integration of system ODE under specific conditions in adsorption problem

I am trying to solve the system of ODEs below. I am applying the finite differences to z, so I get a system of ODE that I can solve with a solver like ode45. The problem is that under the conditions ...
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0answers
24 views

Water distribution through N x Needle orifices

Consider a water distribution setup consisting of a feeder line blocked at one end but having 100 needle outlets all the same size. The feeder line cross sectional area is much greater than a needle ...
1
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0answers
23 views

How do I correctly model this system of torsion springs?

I am currently designing a symmetric parallel mechanism that can be modeled as follows: Here, $\tau^j$ denotes actuator moments and $k_i$ are torsion springs constants. For a specific point in the ...
1
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0answers
15 views

how to get more number variance compared as the csv output file of two model stl files in Cloudcompare

we are using the CloudCompare for comparing two mouth STL model for Final doctoral theses, like works done in this paper(pdf) shown blow: and the instruction said here: so i have tried to insert the ...
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0answers
17 views

Visualization/Verification software for interacting parts e.g. Gears etc

Not sure if there is any software that would model the movements of physical parts, or if even they can move with the given configurations ( software engineer background, no idea the lingo used here )....
1
vote
1answer
172 views

How to calculate initial concentration of first-order reaction in CSTR?

(This question comes from a Chemical Engineering background, but basic Math and Programming knowledge is also required. I hope it still falls in the scope of engineering.stackexchange.com If not, ...
1
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0answers
82 views

Distance travelled at articulation point of turning vehicle

Problem outline: I'm trying to figure out the distance travelled at the articulation point of a turning vehicle with 4 driven wheels (each wheel houses a motor and can all rotate at different RPMs). ...
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0answers
17 views

Modeling of a Wireless Channel with known BER

I have to model through software a wireless (my choice: 3g,4g, 802.11...) channel with given Bit Error Rate. I'm searching some distributions, I'm reading tons of papers but I can't find how to ...
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0answers
106 views

Am I estimating thrust of a ducted fan correctly?

I'm asking if I'm doing this correctly. I've estimated the thrust of a ducted-fan model aircraft neglecting pressure changes across the duct as follows: $$F = Q * \rho * (V_e - V_0)$$ $$= Q * rho * (...
1
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0answers
122 views

Method to simulate a dipole antenna in salt water?

I am looking to simulate the radiation pattern of a 2.7Ghz half-wavelength dipole antenna immersed in salt water. I've been using Altair FEKO software to try and accomplish this. I've tried two ...
1
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0answers
151 views

Modelling acoustic instruments — predicting frequencies, decays, levels, and phases of modes of a circular membrane (drum head)

I have been working on some acoustic synthesis software for modelling several acoustic instruments. I am using the principle of modal synthesis, where every mode of vibration is individually ...
1
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0answers
21 views

How to find the maximum misalignment from vibration?

Consider the system in the (drawn in Paint) image. Assume that there is an input acceleration at the ground defined by a PSD. This acceleration can be in any axis. Points A and B are initially aligned ...
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0answers
24 views

Linear Guidance law into X-Y axis

Im currently writing a model for a guidance law named Maintaining Guidance law. The law looks as following: $$ a_{M} = [K_1,K_2]*[\dot{\lambda_T} ,\dot{\lambda_D}]'$$ Since im using a linear model I ...
1
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0answers
256 views

How to model ball joint in Patran/Nastran?

I would like to model below mechanical system in Patran. But, I don't know how to configure boundary condition of ball joint. The ball joint is spherically rotated. When the described system is in ...
1
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0answers
135 views

What are the various lumped element dynamic system models called?

What are the various lumped element dynamic system models called? By lumped element dynamic system models, I mean the various nodal models comprised of things that look like capacitors, inductors, ...
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0answers
194 views

How is rolling resistance accounted for in the Pacejka Curves?

I am simulating the acceleration of a car (FSAE) in a straight line. I have data of the Pacejka Curves ($F_x$ vs. $SR$) of the tire we will be using. The thing is that the curve doesn´t pass through ...
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0answers
30 views

Autodesk Inventor Constraints for Clockwise / Counterclockwise / Dead Points

In the YouTube video Spherical 4-Bar Infinity Mechanism by Thang010146, Dead Points are not compensated for by mechanical means. How can Autodesk Inventor Constraints be applied to such a mechanism to ...
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0answers
104 views

Efficiency model for centrifugal pumps, using relations from Europump's Ecopump project

Context: I'm trying to create a mathematical model for centrifugal pumps. This model should describes how the operational variables of centrifugal pumps $(Q, \Delta P, ...)$ related to it's design ...
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0answers
43 views

Verify parameters variation in local sensitivity coefficients for microkinetic model

I’m performing a sensitivity analysis for a model of a set of elementary chemical reactions. I’m considering the variation in species concentration ($c_{k}$) with respect to the forward reaction rate ...
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0answers
30 views

Examples of model-based control techniques

I am trying to find out the differences between the model-based control approach and the data-driven one. Surely the main difference is the latter's independence from the information of the ...
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0answers
25 views

propeller air mass flow equation

I am trying to model a hovercraft and I need to obtain an air inlet flow ratio in (kg / s) of a propeller based on its dimensions (it can be the radius) and speed, is there an equation like that? ...
0
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0answers
23 views

Find orientation of reference nodes in Abaqus

I am constructing a simplified model of a pontoon-supported floating bridge in Abaqus. I have chosen to represent the pontoons as one-noded user-elements defined from the mass and stiffness matrix for ...
0
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0answers
32 views

Are there examples of spring-mass-damper system that exhibit increasing growth in an unstable way

Simply, are there examples of spring-mass-damper systems that exhibit unbounded behavior or at least increasing behavior for a period of time. I am trying to do some vibrations research, but I am ...
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0answers
16 views

What is the order of execution in system models?

I'm learning SysML/MBSE right now. In what order is a model "executed", that is: in what order are dependencies between properties reconciled? For instance, if I have one component/subsystem ...
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0answers
23 views

Magnetomotive forces acting on assembly

Apologies if this is the wrong place to pose this question, or if it is poorly formulated, I would appreciate any help, even if that is pointing me to a place where I can learn more about solving ...
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0answers
39 views

Optimal control of the gradient type PDE

I recently encountered the following optimal control problem. The purpose of the system is to find the parameter $x$ at which the maximum or minimum of the function $f$ a is reached. $x$ is unknown to ...
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0answers
32 views

Are gas distribution networks tree-like?

I was wondering, if it is justified to say, that gas distribution network graphs (primarily in Europe) are typically tree-like. By gas distribution networks I mean municipal and regional distribution ...
0
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1answer
152 views

Pspice ac sweep problem

I want to run an AC sweep from 1 Hz - 10 MHz and calculate the output of the circuit (the voltage on RL), however spice shows that my voltage is 0 in a lot of parts that it shouldn't. I believe the ...
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0answers
54 views

Lagrangian of a piezoelectric material

I'm confused about the Lagrangian of a piezoelectric material. I've seen multiple sources which seem to contradict each other. The way I personally approach the problem is the following ($\underline{...
0
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1answer
49 views

Modelling Soil in a Scale Model

I'm building a scale model for a proposed construction project. Is it possible to simulate foundations operating in soil in a scale model? What do people typically use?