Coffee Lake Configurations for Computational Fluid Dynamics and Gaming with no Mechanical Storage, Pakistani Market Prices.

     These setups feature no mechanical hard drive(s).

Estimated price PKR 205,000.

     For the processor, choose the Intel Core i7-8700 for PKR 43,000. Motherboard of choice should be the Gigabyte Z370 AORUS Gaming 3 for PKR 20,500. For memory, go with the Corsair Vengeance LPX 1x16GB DDR4-3000 for PKR 23,000. Samsung 850 EVO 1TB SSD for PKR 39,500 should be the only storage option. The Gigabyte GV-N1080WF3OC-8GD GeForce GTX 1080 for PKR 68,500 graphics card. The Corsair Carbide SPEC-04 Casing for PKR 5,500. Powering the whole thing should be at least a Thermaltake Lite-Power 550W PSU for PKR 4,400.

Estimated price PKR 157,000.

     For the processor, choose the Intel Core i7-8700 for PKR 43,000. Motherboard of choice should be the Gigabyte Z370 AORUS Gaming 3 for PKR 20,500. For memory, go with the Corsair Vengeance LPX 1x16GB DDR4-3000 for PKR 23,000. Samsung 850 EVO 1TB SSD for PKR 39,500 should be the only storage option. The Asus PH-GTX1050TI-4G GTX 1050Ti for PKR 21,300 graphics card. The Corsair Carbide SPEC-04 Casing for PKR 5,500. Powering the whole thing should be at least a Thermaltake Lite-Power 550W PSU for PKR 4,400.

Estimated price PKR 167,500.

     For the processor, choose the Intel Core i5-8700 for PKR 23,000. Motherboard of choice should be the Gigabyte Z370 AORUS Gaming 3 for PKR 20,500. For memory, go with the Corsair Vengeance LPX 1x16GB DDR4-3000 for PKR 23,000. Western Digital Green 240GB and Blue 500GB SSD for PKR 9,500 and PKR 17,500 should be the storage options. The Gigabyte GV-N1080WF3OC-8GD GeForce GTX 1070Ti for PKR 64,000 graphics card. The Corsair Carbide SPEC-04 Casing for PKR 5,500. Powering the whole thing should be at least a Thermaltake Lite-Power 550W PSU for PKR 4,400.

Estimated price PKR 137,000.

     For the processor, choose the Intel Core i5-8700 for PKR 23,000. Motherboard of choice should be the Gigabyte Z370 AORUS Gaming 3 for PKR 20,500. For memory, go with the Corsair Vengeance LPX 1x16GB DDR4-3000 for PKR 23,000. Western Digital Blue 500GB SSD for PKR 17,500 should be the storage option. The Asus STRIX-GTX1060-DC2O6G GTX 1060 for PKR 43,000 graphics card. The Corsair Carbide SPEC-04 Casing for PKR 5,500. Powering the whole thing should be at least a Thermaltake Lite-Power 550W PSU for PKR 4,400.

Estimated price PKR 106,000.

     For the processor, choose the Intel Core i3-8100 for PKR 14,500. Motherboard of choice should be the Gigabyte Z370 AORUS Gaming 3 for PKR 20,500. For memory, go with the Corsair Vengeance LPX 1x16GB DDR4-3000 for PKR 23,000. Western Digital Blue 500GB SSD for PKR 17,500 should be the storage option. The Asus PH-GTX1050TI-4G GTX 1050Ti for PKR 21,300 graphics card. The Corsair Carbide SPEC-04 Casing for PKR 5,500. Powering the whole thing should be at least a Thermaltake Lite-Power 450W PSU for PKR 3,800.

     Only the first configuration is suitable for both gaming and computational fluid dynamics (CFD). If you need a system for CFD alone, then the second configuration will be sufficient, all other configurations can be referred to as general purpose gaming PCs.

Wind Turbine SolidWorks Flow Simulation Premium Computational Fluid Dynamics: Verification and Validation

Numerical Methodology

Computational Fluid Dynamics analysis was performed using commercially available code SolidWorks Flow Simulation Premium© in the present study. SolidWorks Flow Simulation Premium© is a CAD embedded CFD tool; employs κ-ε turbulence model with damping functions, SIMPLE-R (modified) as the numerical algorithm and second order upwind and central approximations as the spatial discretization schemes for the convective fluxes and diffusive terms. The time derivatives are approximated with an implicit first-order Euler scheme. The Flow Simulation© solves the Navier-Stokes equations; mentioned below; which are formulations of mass and momentum conservation laws for fluid flows. To predict turbulent flows, the Favre-averaged Navier-Stokes equations are used.

∂ρ/∂t+∂(ρui)/∂xi=0

∂(ρui)/∂t+∂(ρuiuj)/∂xj+∂p/∂xi= ∂(τij+τijR)/∂xj+Si     i=1,2,3

where, Si is a mass-distributed external force per unit mass due to a porous media resistance (Siporous), a buoyancy (Sigravity=-ρgi is the gravitational acceleration component along the i-th coordinate direction) and the coordinate system’s rotation (Sirotation), i.e., Si=Siporous+Sigravity+Sirotation. The subscripts are used to denote summation over the three coordinate directions.

All the simulations were performed to predict three-dimensional transient flow over the wind turbine. The Local rotating region(s) (Sliding) feature within SolidWorks Flow Simulation Premium© software was employed to simulate the wind turbine’s rotation in standard atmosphere.

Validation and Verification

To ensure validation of the numerical methodology, the numerical results of the present study were compared with the experimental results. A total of six tip-speed ratios were selected for the present study, as mentioned in table 1. The NREL Phase VI wind turbine without contra-rotating technology was selected for validation and verification because there is no reliable experimental data available for the NREL Phase VI wind turbine incorporating the contra rotating technology. The operating rotational velocity for the NREL Phase VI wind turbine is 7.5 rad.s-1. The diameter of the wind turbine is 10.058 m.

Table 1; TSR and the corresponding wind speeds

TSR	Wind Speed [ms-1]
7.5	5
5.03	7.5
3.77	10
3.02	12.5
2.52	15
1.89	20

The comparison between the experimentally determined shaft torques and numerical results of the present study, along with the number of mesh cells and the time step employed at various wind speeds is shown in table 2. A comparison of the present study with other studies conducted on the NREL Phase VI wind turbine is presented in Figure 1.

The computational domain selected had a size of 4Dx4Dx2.8D. The computational domain had a large enough volume to accurately trace the fluid flow around the wind turbine and for the solver to operate without any reversed flow or unwanted vortex formation or any other numerical difficulties.

Flow Simulation© considers the real model created within SolidWorks© and automatically generates a Cartesian computational mesh in the computational domain distinguishing the fluid and solid domains. The resulting mesh, employs the immersed boundary method, has three types of cells, namely Fluid cells; the cells located entirely in the fluid, Solid cells; the cells located entirely in the solid and Partial cells are the cells which are partly in the solid and partly in the fluid [22]. The Cartesian mesh with immersed boundary method has certain advantages, like the mesh is very quick to generate and results in high quality elements. The solution converges faster and the mesh distortion and numerical errors are relatively lower. During the process of mesh generation, it was made sure that the region of interest; the region immediately surrounding the wind turbine; had a very fine mesh as compared to the boundaries of the computational domain, to make the simulations converge. The Local Mesh option within the SolidWorks Flow Simulation Premium© software was employed to increase the mesh density in the critical areas.

Table 2; Comparison of the Experimental and Numerical Results

Wind Speed [ms-1]	Experimental Power [W]	Numerical Power [W]	Percentage Difference	Mesh Cells [x105]	Time Step [x10-3 s]
5	2,000	2,043	2.1	3.77	5.41
7.5	6,000	6,105	1.72	3.77	5.41
10	10,000	10,230	2.25	3.77	5.41
12.5	9,500	9,343	1.65	7.79	1.9
15	9,000	7,606	15.49	7.79	1.9
20	8,500	8,696	2.25	9.21	1.96

Figure 1; Comparison of results from present study with previous works

Project Files and Illustrations
     The project files are available here. An illustration of the rotor is provided below.

CFD Post Processing

SolidWorks Animation: Transient NREL Phase-VI Wind Turbine CFD Simulation [Validated]

     10 KW wind turbine CFD simulation using Flow Simulation Premium. Design points: 10 m/s wind speed, rotational velocity 7.5 rad/s.

     The rendered volume shows vorticity (curl of the velocity field). It is colored by dynamic pressure. Low pressure in the center of the helix shows very small wind speed.

     Power from the CFD analysis was 9,854.96 W while the experimental power is 10,000 W, a difference of only 1.45 %, that too by using only 693,141 cells in the mesh.

     Do you want me to make a tutorial about the simulation setup with SolidWorks Flow Simulation Premium?

Bond Graphs from System Dynamics: Modeling, Simulation, and Control of Mechatronic Systems (Dean C. Karnopp) Chapter Four (4.1i, 4.1j and 4.2a.)

4.1i

4.1j

4.2a

Bond Graphs from System Dynamics: Modeling, Simulation, and Control of Mechatronic Systems (Dean C. Karnopp) Chapter Four (4.1e, 4.1f ,4.1g, 4.1h.)

4.1e

 

4.1f

4.1g

 

4.1h

 

Bond Graphs from System Dynamics: Modeling, Simulation, and Control of Mechatronic Systems (Dean C. Karnopp) Chapter Four (4.1a, 4.1b, 4.1c, 4.1d)

4.1a

4.1b

 4.1c

 4.1d

Bond Graph Representation of the Coaxial Contra-Rotating Propeller (with the Bond-Graph)

A contra rotating propeller, with five gears and seven shafts.

Se	Source of effort; voltage supplied by the power source; a Li-Po battery in this study.
Rw	Motor winding resistance.
Iw	Motor winding inductance.
GY	dc Motor; a Gyrator.
T	Gyrator Modulus.
bs1	Bearing resistance on shaft number one.
Js1	JS1=Js’1+Jg1+Jr.
Js1	Total inertia for shaft number one.
Js’1	Inertia of shaft number one.
Jg1	Inertia of gear number one.
Jr	Inertia for dc motor rotor.
Ks1	Stiffness of shaft number one.
Ms1	Ms1=Ms’1+Mm+Mg1.
Ms1	Total mass for the shaft number one.
Ms’1	Mass for the shaft number one.
Mm	Mass for the dc motor.
Mg1	Mass for the gear number one.
m1	Distance from the center of mass of the Ms1 to the shaft number one; moment arm to transform the torque in to force to be applied to the Ms1.
TF	Transformer, mechanical transformer in this study, spur gear mesh.
Rs12	Transformer Modulus, transmission ratio between shaft number one and two.
bs2	Bearing resistance on shaft number two.
Js2	JS2=Js’2+ Jg2+Jg6.
Js2	Total inertia for shaft number two.
Js’2	Inertia of shaft number two.
Jg2	Inertia of gear number two.
Jg6	Inertia of gear number six.
Ks2	Stiffness of shaft number two.
Ms2	Ms2=Ms’2+Mg6+Mg2.
Ms2	Total mass for the shaft number two.
Ms’2	Mass for the shaft number two.
Mg6	Mass for the gear number six.
Mg2	Mass for the gear number two.
m2	Distance from the center of mass of the Ms2 to the shaft number two; moment arm to transform the torque in to force to be applied to the Ms2.
Rs23	Transformer Modulus, transmission ratio between shaft number two and three.
bs3	Bearing resistance on shaft number three.
Js3	JS3=Js’3+ Jg3+Jg4.
Js3	Total inertia for shaft number three.
Js’3	Inertia of shaft number three.
Jg3	Inertia of gear number three.
Jg4	Inertia of gear number four.
Ks3	Stiffness of shaft number three.
Ms3	Ms2=Ms’2+Mg3+Mg4.
Ms3	Total mass for the shaft number one.
Ms’3	Mass for the shaft number three.
Mg3	Mass for the gear number three.
Mg4	Mass for the gear number four.
m3	Distance from the center of mass of the Ms3 to the shaft number three; moment arm to transform the torque in to force to be applied to the Ms3.
Rs34	Transformer Modulus, transmission ratio between shaft number three and four.
bs4	Bearing resistance on shaft number four.
Js4	JS4=Js’4+ Jg5+Jp1.
Js4	Total inertia for shaft number four.
Js’4	Inertia of shaft number four.
Jg5	Inertia of gear number five.
Jp1	Inertia of propeller number one.
Ks4	Stiffness of shaft number three
Ms4	Ms4=Ms’4+Mg5+Mp1.
Ms4	Total mass for the shaft number four.
Ms’4	Mass for the shaft number four.
Mg5	Mass for the gear number five.
Mp1	Mass for the propeller number one.
m4	Distance from the center of mass of the Ms4 to the shaft number four; moment arm to transform the torque in to force to be applied to the Ms4.
Rs25	Transformer Modulus, transmission ratio between shaft number two and five.
bs5	Bearing resistance on shaft number five.
Js5	JS5=Js’5+ Jg7+Jp2.
Js5	Total inertia for shaft number five.
Js’5	Inertia of shaft number five.
Jg7	Inertia of gear number seven.
Jp2	Inertia of propeller number two.
Ks5	Stiffness of shaft number five.
Ms5	Ms4=Ms’5+Mg5+Mp2.
Ms5	Total mass for the shaft number four.
Ms’5	Mass for the shaft number five.
Mg7	Mass for the gear number seven.
Mp2	Mass for the propeller number two.
m5	Distance from the center of mass of the Ms5 to the shaft number five; moment arm to transform the torque in to force to be applied to the Ms5.
RPS	RPS=KT1/(KQ1*D1)
RPS	Transformer Modulus, for propeller number one.
KT1	Coefficient of thrust for propeller number one.
KQ1	Coefficient of torque for propeller number one.
D1	Diameter for propeller number one.
KT1	KT1=Tp1/(Rho*n12*D14)
KQ1	KQ1=Qp1/(Rho*n12*D15)
Tp1	Thrust from propeller number one.
n1	Speed for propeller number one, in rev/s.
Qp1	Torque required to rotate propeller number one.
P1	Propeller number one, mounted on the shaft number four.
RPH	RPH=KT2/(KQ2*D2)
RPH	Transformer Modulus, for propeller number 2.
KT2	Coefficient of thrust for propeller number two.
KQ2	Coefficient of torque for propeller number two.
D2	Diameter for propeller number two.
KT2	KT=Tp2/(Rho*n22*D24)
KQ2	KQ=Qp2/(Rho*n22*D25)
Tp2	Thrust from propeller number two.
Rho	Density of the fluid, air in this study.
n2	Speed for propeller number two, in rev/s.
Qp2	Torque required to rotate propeller number two.
P2	Propeller number two, mounted on the hollow shaft; only of the system, shaft number five.
mc1	Distance from the center of mass of the chassis to the shaft number one; moment arm to transform torque in to force to be applied to the chassis.
mc2	Distance from the center of mass of the chassis to the shaft number two; moment arm to transform torque in to force to be applied to the chassis.
mc3	Distance from the center of mass of the chassis to the shaft number three; moment arm to transform torque in to force to be applied to the chassis.
mc4	Distance from the center of mass of the chassis to the shaft number four; moment arm to transform torque in to force to be applied to the chassis.
mc5	Distance from the center of mass of the chassis to the shaft number five; moment arm to transform torque in to force to be applied to the chassis.
Mc	Mass of the chassis.