Completed Projects and Researches

CFD study of plain flapped NACA 0012 airfoil subjected to different flap angles and Mach numbers

  • The simulation process was validated with previously documented work of NASA Langley Research Center. (Link)
  • k - omega shear stress transport (SST) model was used, as it yields best computational results according to Eleni et. al. (PDF)
  • Flap angles were changed from 10 degree to 50 degree at 10 degree interval for every mach number. Coefficient of lift and drag (Cl and Cd)for each flap angles were observed. 
  • Increasing flap angles surely increase lift coefficient (Cl). However, Cl/Cd and root(Cl)/Cd decreases dramatically. Which in turn causes lower Range and Endurance.
Variation of lift coefficient (CL) with Mach
number (M) for different flap angle (δ)
Variation of drag coefficient (CD) with
Mach number (M)

Physical mechanism of drag divergence in
Fig. 17 for 20 degrees of flap angle (δ) (a) Flow field
at point, a (b) Flow field at point, b (c) Flow field at
point, c

Variation of drag coefficient (CD) with
Mach number (M) for different flap angle (δ)

Variation of CL/CD with Mach number (M)
for different flap angle (δ)
 

Performance investigation of building ventilation system by HVAC simulation 

  • A HVAC case study done in SolidWorks flo simulation.
  • Forced inlet fresh air flow and Forced air removal were assumed 4.8 m3/min and 2.6 m3/min respectively
  • LAQI (Local Air quality index), PMV (Predicted Mean Vote), PPD (Predicted Percent Dissatisfied) were observed for the operating conditions. 
  • If was found that the room was close to slightly warm (PMV = 0.7) for the test operating conditions. However, this is slightly higher than acceptable range (-0.5≤ PMV ≤+0.5) according Vladimir Zmhral et. al. (PDF)


simplified model of a hospital room
Isosurfaces interpreting PMV
Cut plot by LAQI of expired air

Optimum Design of Autofrettaged Thick-Walled Cylinders

  • Comparison with Zhu & Yang’s (LINK) model has been done in determination of optimum elasto-plastic radius, ropt and optimum autofrettage pressure, Popt.
  • Flow stress distribution along the cylinders remains same for same k (Ro/Ri) values.
  • Percentage of reduction of maximum Von Mises stress increases as value of k and working pressure increases.
  • Effect of loading stages on autofrettage process is also investigated. As long as the pressures in first and last stage remains constant, there is no effect of loading stages on autofrettage process; no matters how many stages prevails between these two pressures.
Variation of Maximum von Mises Stresses at Different Elasto-plastic Radius for Different k values
Variation of Maximum von Mises Stresses Correspond to Optimum Elasto-plastic Radius for Different k values
Variation of Maximum von Mises Stresses at Different Autofrettage Pressure
Variation of Maximum von Mises Stresses at Different Autofrettage Pressure for Different Working Pressure
Variation of Maximum von Mises Stresses at Different Autofrettage Pressure for Different Values of k at 100 MPa Working Pressure keeping inner radius constant
Variation of Maximum von Mises Stresses at Different Autofrettage Pressure for Different Values of k at 100 MPa Working Pressure keeping outer radius constant