Difference between revisions of "Hamza Khamis Kombo"
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Problem Statement: Given a metal rod of length L, fixed at one end, let's find the displacement π’(π₯,π‘) along the rod's length as a function of both space x and time t. The rod is initially displaced and then allowed to vibrate freely. | Problem Statement: Given a metal rod of length L, fixed at one end, let's find the displacement π’(π₯,π‘) along the rod's length as a function of both space x and time t. The rod is initially displaced and then allowed to vibrate freely. | ||
Governing Equation: 1D Wave Equation For axial vibrations in the rod, the displacement u(x,t) satisfies the 1D wave equation, βd2u/dt2=c2.d2u/dx2. where:π’(π₯,π‘) is the displacement of the rod at position x and time π‘. π=(πΈ/π)^1/2 is the wave speed in the material, E is the Young's modulus of the material (e.g., for steel, πΈ=200Γ10^9N/m2, Ο is the density of the material (e.g., for steel, π=7850kg/m3. For steel, the speed of waves traveling along the rod is πβ5050m/s. | Governing Equation: 1D Wave Equation For axial vibrations in the rod, the displacement u(x,t) satisfies the 1D wave equation, βd2u/dt2=c2.d2u/dx2. where:π’(π₯,π‘) is the displacement of the rod at position x and time π‘. π=(πΈ/π)^1/2 is the wave speed in the material, E is the Young's modulus of the material (e.g., for steel, πΈ=200Γ10^9N/m2, Ο is the density of the material (e.g., for steel, π=7850kg/m3. For steel, the speed of waves traveling along the rod is πβ5050m/s. | ||
β | + | Boundary and Initial Conditions: | |
1.Boundary Condition: The rod is fixed at π₯=0, so π’(0,π‘)=0. | 1.Boundary Condition: The rod is fixed at π₯=0, so π’(0,π‘)=0. | ||
2.Initial Conditions: Initial displacement π’(π₯,0), which we can assume is a simple sinusoidal displacement such as π’(π₯,0)=π΄sin(ππ₯πΏ). Initial velocity βπ’/βπ‘(π₯,0)=0. | 2.Initial Conditions: Initial displacement π’(π₯,0), which we can assume is a simple sinusoidal displacement such as π’(π₯,0)=π΄sin(ππ₯πΏ). Initial velocity βπ’/βπ‘(π₯,0)=0. |
Revision as of 22:33, 11 November 2024
Name: Hamza Khamis Kombo NPM: 2306259553 Mechanical Engineering- S2
First, Lecture material (29/10/2024)
Conscious Thinking Heartware-Brainware (variable), Initiator, Intention, Initial Thinking, Idealization, Instruction. DAI5 is a problem solving method developed by Dr. Ahmad Indra from the University of Indonesia. This method is known as "Conscious Thinking" and focuses on the thinking process starting from intention to selecting tools as the final step. DAI5 is a concept that integrates heartware and brainware aspects to form conscious and focused thought patterns and attitudes. This approach uses five core variables which are expected to create balance between the mind, heart and human actions. The following is an explanation of these five variables. Initiator: refers to the initial trigger or impulse that starts the thought or action process. This initiator is the main source of energy or motivation that triggers a person to start a certain idea, project, or action. In the context of DAI5, this initiator may arise from within oneself, such as needs, values, or desires, or from outside, such as opportunities or challenges faced. Intention: is the clarity of the purpose of the action or thought that you want to realize. This intention is very important because it gives direction and meaning to the process of thinking or acting. With strong and positive intentions, individuals can undergo the next process with stable focus and motivation. Intention is a bridge between internal desires and the goals to be achieved. Initial Thinking: The Initial Thinking is the stage where initial ideas and possibilities are formulated. Here, individuals begin to map out thoughts, consider options, and explore different perspectives. This initial thought becomes the foundation for planning the next steps. At this stage, a person also learns to recognize obstacles, opportunities, and resources needed to achieve goals. Idealization: is the process of forming an ideal image or vision of the final result you want to achieve. In this stage, individuals imagine the desired results and set standards or ideal values ββthat they want to realize. Idealization helps someone to focus on the best potential of the expected results and maintain enthusiasm and perseverance in achieving them. Instruction set: This is the final stage, where specific direction or guidance begins to be implemented to achieve the goal. These can be concrete steps, strategies, or established methods to achieve an idealized vision. Instruction functions as a blueprint that guides actions until the final result is achieved. conclusion: These five variables, Initiator, Intention, Initial Thinking, Idealization, and Instruction are interrelated and form a structured conscious thinking process. DAI5 Conscious Thinking aims to create a thought pattern that is in harmony between the heart and brain, resulting in effective, meaningful and responsible actions. This approach is highly relevant for increasing self-awareness and decision quality, especially in personal and professional development.
Heat pipes are efficient devices for heat transfer, often involving phase change. The basic heat conduction equation for a 1D system, known as Fourierβs law, can be described by the PDE:
βπ/βπ‘ =πΌ.β2π/βπ₯2 where: T is the temperature, t is time, x is the spatial coordinate along the pipe length, πΌ=π/πc is the thermal diffusivity, with k being thermal conductivity, π the density, and c the specific heat.Heat Pipe Modifications In a heat pipe, we also consider phase change dynamics and latent heat. Therefore, an additional term for latent heat needs to be incorporated, leading to:
βπ/βπ‘=πΌ.β2π/βπ₯2+πΏβπ/pcβπ‘. where βπ/βπ‘ represents the phase change rate (e.g., vaporization and condensation along the pipe length).The algorithm to solve this heat pipe equation typically involves: Initialize Parameters: Set the initial temperature distribution, thermal properties (thermal diffusivity, latent heat, etc.), and boundary conditions. Discretize the PDE: Apply finite difference discretization (e.g., Forward-Time Centered-Space scheme) to convert the continuous PDE into a system of algebraic equations. Iterate Over Time Steps: Calculate temperature at each spatial node using the discretized equation. Update the temperature field based on the phase change rate term. Check for Convergence or Completion: Continue until a steady-state or a predefined number of time steps is reached.
Here's a simplified flowchart for the heat pipe simulation:
Start Initialize Parameters Set Initial Conditions For Each Time Step: Calculate the heat transfer rate for each spatial node.
Update temperature with phase change term. Check Convergence: If converged, end simulation; else, continue. End
Python Code
The following code implements a simple finite difference solution to this heat transfer equation with an added phase change term
import numpy as np import matplotlib.pyplot as plt# Constants
L = 1.0 # Length of the heat pipe (m) T_initial = 300 # Initial temperature (K) alpha = 1e-5 # Thermal diffusivity (m^2/s) L_heat = 200000 # Latent heat of phase change (J/kg) rho = 1000 # Density (kg/m^3) c = 1000 # Specific heat (J/(kg*K)) dx = 0.01 # Spatial step (m) dt = 0.1 # Time step (s) nx = int(L / dx) # Number of spatial points nt = 500 # Number of time steps
- Initialize temperature field
T = np.full(nx, T_initial) T_new = T.copy()
- Boundary conditions
T[0] = 400 # Left boundary (hot) T[-1] = 300 # Right boundary (cold)
- Heat equation solver with phase change term
for t in range(nt):
for i in range(1, nx - 1): phase_change = L_heat / (rho * c) * (T[i] > 373) # Phase change at 373 K T_new[i] = T[i] + alpha * dt / dx**2 * (T[i+1] - 2*T[i] + T[i-1]) + phase_change # Update temperature T = T_new.copy()
- Plotting the final temperature distribution
plt.plot(np.linspace(0, L, nx), T) plt.xlabel('Position along pipe (m)') plt.ylabel('Temperature (K)') plt.title('Temperature Distribution in Heat Pipe') plt.show(). This code approximates the heat transfer along a 1D heat pipe, including a basic model for phase change. Adjustments in the code (like boundary conditions, number of iterations, or temperature limits) can help refine the simulation based on specific heat pipe properties. This solution provides a straight forward foundation, but additional refinements may include more precise boundary handling, variable thermal properties, or more complex phase change models.(https://chatgpt.com/c/67288205-50f0-8008-90d8-b8cca45d8287).
ASSIGNMENT-2 (11/11/2024)
Question I asking to chart GPT: can you give me a practical example along with a simple calculator such as 1D problem, in engineering that continuum mechanical treats materials as continuous, on integration of uninterrupted" conscious continuum into the DAI5 framework?
Answer from Chart GPT: To illustrate the integration of "uninterrupted conscious continuum" in the DAI5 framework through a continuum mechanics example, let's consider a straightforward engineering problem in 1D stress analysis. Weβll analyze a simple case where the material is treated as continuous and apply the DAI5 framework for step-by-step problem solving.
Example Problem: 1D Axial Loading of a Steel Rod: Imagine a steel rod with uniform cross-section π΄=2cm^2 and length, πΏ=1m, fixed at one end. A force πΉ=1000N is applied at the other end. Using continuum mechanics principles, we want to find the elongation (ΞπΏ) of the rod. We'll approach the solution using the DAI5 method as follows: Step 1, Intention: We aim to determine the axial elongation of a steel rod under a specific load using 1D stress-strain relationships. The rod is treated as a continuous, homogeneous material, meaning we assume no breaks or gaps in the material for simplicity. Step 2, Initial Thinking: We hypothesize that the steel rod, subjected to axial loading, will undergo a uniform elongation along its length, as described by Hooke's Law. For small deformations, this relationship is: Ο=Eβ Ξ΅ where:π is the stress,πΈ is the Young's modulus of steel (πΈ=200Γ10^9 N/m^9for steel),π is the strain. Since π=πΉ/π΄= AF and π=ΞπΏ/L, we can rewrite Hookeβs Law to find the elongation. Step 3, Idealization: In this stage, we treat the rod as a perfectly elastic material without any imperfections or discontinuities. This simplifies our calculations and allows us to focus on a straightforward elastic response. Given the uniform stress distribution and material continuity, the rod will stretch uniformly across its length. The problem now reduces to finding ΞπΏ under the applied force. Step 4, Instruction Set (Calculation): Calculate Stress, π=πΉ/π΄ =1000N/2Γ10^-4m2=5Γ10^6N/m^2. Calculate Strain, π:=π/πΈ =(5Γ10^6N/m^2)/(200Γ10^9N/m^2)=2.5Γ10^β5. Calculate Elongation, ΞπΏ=πβ πΏ=(2.5Γ10^β5)Γ1m= 0.025mm Step 5, Uninterrupted Conscious Continuum in DAI5 Framework: Here, we think of the uninterrupted continuum of conscious awareness as a steady understanding and recognition of the material's response across its entire length, without abrupt changes or singularities. Throughout the DAI5 process, thereβs a conscious observation of the material's consistent behavior under loadβwithout micro-breaks or microscopic failuresβuntil it deforms linearly according to Hookeβs Law. The DAI5 framework allows us to approach such problems with structured, incremental awareness, where each stage reaffirms the continuity and uniformity of the material's response to load. In this problem, we demonstrated how, by using the DAI5 framework with continuum mechanics, we maintained a "conscious" and uninterrupted understanding of the material's behavior. The simplified calculation illustrates how the continuum concept operates within a controlled and predictable scope, aiding engineers in assessing material response.
I asking again to chart GPT. can you give me an example of a question related to 1D PDE on this beam ( metal rod) and also give me code? Certainly! Letβs explore a classic 1D partial differential equation (PDE) for axial vibration along the length of the metal rod. This PDE describes how the displacement π’(π₯,π‘) of any point π₯ along the rod changes over time π‘, which is useful in analyzing vibrations in beams and rods. Problem Statement: Given a metal rod of length L, fixed at one end, let's find the displacement π’(π₯,π‘) along the rod's length as a function of both space x and time t. The rod is initially displaced and then allowed to vibrate freely. Governing Equation: 1D Wave Equation For axial vibrations in the rod, the displacement u(x,t) satisfies the 1D wave equation, βd2u/dt2=c2.d2u/dx2. where:π’(π₯,π‘) is the displacement of the rod at position x and time π‘. π=(πΈ/π)^1/2 is the wave speed in the material, E is the Young's modulus of the material (e.g., for steel, πΈ=200Γ10^9N/m2, Ο is the density of the material (e.g., for steel, π=7850kg/m3. For steel, the speed of waves traveling along the rod is πβ5050m/s. Boundary and Initial Conditions: 1.Boundary Condition: The rod is fixed at π₯=0, so π’(0,π‘)=0. 2.Initial Conditions: Initial displacement π’(π₯,0), which we can assume is a simple sinusoidal displacement such as π’(π₯,0)=π΄sin(ππ₯πΏ). Initial velocity βπ’/βπ‘(π₯,0)=0. Python Code to Solve the PDE: The following code uses the finite difference method to solve the 1D wave equation for a vibrating steel rod. This approach discretizes the spatial and time dimensions and solves the equation numerically.
import numpy as np import matplotlib.pyplot as plt import matplotlib.animation as animation
# Parameters L = 1.0 # Length of the rod (in meters) T = 0.01 # Total time (in seconds) Nx = 100 # Number of spatial points Nt = 1000 # Number of time points A = 0.01 # Initial amplitude of displacement (in meters)
# Material properties for steel E = 200e9 # Young's modulus (N/m^2) rho = 7850 # Density (kg/m^3) c = np.sqrt(E / rho) # Wave speed (m/s)
# Discretization dx = L / (Nx - 1) # Spatial step size dt = T / Nt # Time step size r = (c * dt / dx) ** 2 # Stability parameter
# Check stability condition if r > 1: raise ValueError("Stability condition violated: reduce dt or increase dx.")
# Initialize displacement array u = np.zeros((Nx, Nt)) # Displacement at each point and time x = np.linspace(0, L, Nx) # Spatial grid
# Initial condition: sinusoidal initial displacement u[:, 0] = A * np.sin(np.pi * x / L) u[:, 1] = u[:, 0] # Initial velocity is zero
# Finite Difference Method to solve the wave equation for n in range(1, Nt - 1): for i in range(1, Nx - 1): u[i, n+1] = 2 * u[i, n] - u[i, n-1] + r * (u[i+1, n] - 2 * u[i, n] + u[i-1, n])
# Visualization of the displacement over time fig, ax = plt.subplots() line, = ax.plot(x, u[:, 0]) ax.set_ylim(-A, A) ax.set_xlabel('Position (x)') ax.set_ylabel('Displacement (u)') ax.set_title('Vibration of a Steel Rod')
# Update function for animation def update(n): line.set_ydata(u[:, n]) return line,
# Create animation ani = animation.FuncAnimation(fig, update, frames=Nt, blit=True) plt.show()
Explanation of the Code
Parameters: Define the rodβs length, material properties, discretization points, and stability factor. Initial Conditions: The displacement is initialized as a sine function, representing an initial static deflection. Velocity is initially zero, so π’(π₯,π‘=0)=π΄sin(ππ₯/πΏ). Finite Difference Method: Each pointβs displacement is updated over time using the wave equationβs finite difference form. Visualization: A simple animation of the vibration over time is created to visualize the rodβs oscillations. Interpretation: This code gives a numerical solution to the 1D wave equation and shows the displacement of the rod over time. Using the DAI5 framework, this approach allows you to: Intend: Identify and set up the vibration problem. Initial Thinking: Determine the rodβs initial deflection shape. Idealize: Treat the rod as continuous with uniform material properties. Instruction Set: Use the finite difference method to solve the wave equation. Uninterrupted Conscious Continuum: Observe the vibration evolution smoothly, assuming continuity of material and displacement in space and time. This example illustrates the propagation of waves along a continuous medium, showing how the rodβs vibration evolves without any discontinuity, as per continuum mechanics