Q2. What have the authors contributed in "Algebraic generation of single domain computational grid for twin screw machines part i – implementation" ?
In this paper, a new algebraic boundary distribution of CR type has been implemented to generate a single domain rotor grid.
Q3. What are the future works mentioned in the paper "Algebraic generation of single domain computational grid for twin screw machines part i – implementation" ?
With CR type structure, there was a decrement in the face warp quality at tip of the rotors which will need attention in further work.
Q4. What is the first approach to generating a rotor grid?
The first approach uses coordinate transformation of the full rotor domain and a skewed sine function in the transformed domain adaptable for a given rotor profile.
Q5. What is the function used to determine the nodes associated with each block?
Once the nodes associated with each block are found by the scanning function, an arc-length based projection is used to determine the nodes 𝒓𝒓𝑖𝑖,𝑗𝑗=0(𝑥𝑥,𝑦𝑦) to be placed on the inner boundary - rotor profile.
Q6. What is the function made to work only between the CUSP points?
In the interlobe space where the outer boundary is represented by the rack curve, the sine function is made to work only between the CUSP points.
Q7. What is the significance of the single domain structured grid for the rotors?
a highly significant achievement is a single domain structured grid for therotors which eliminates a non-conformal interface between the two rotor domains, while still maintaining the fully hexahedral cell topology.•
Q8. How many millimetres can be used to determine the distance between the rotor and?
The distance between the rotor and the casing can vary from a few millimetres in the core region to a few micrometres in the clearance regions.
Q9. What is the effect of the sliding action on the rotor?
Due to this sliding action some face warping of the cells are noticeable at the root of the main rotor and at the tip of the gate rotor where normally small fillets are introduced in the rotor profile, as shown in Figure 15.
Q10. What is the main reason for the error in numerical calculations?
If a large numbers of cells are with poor quality then the error induced in numerical calculations is large resulting in inaccurate or false predictions from the CFD models.
Q11. Why are skewness and amplitude factors required to achieve regular distribution in 2D?
Because of these features a relatively high skewness and amplitude factors are required to achieve regular distribution in 2D cross sections.
Q12. What are the main steps in generating the CR type grid?
The main steps in generating the CR type grid are:1. Split the rotor cross section into two O blocks using rack as the splitting curve (Figure 1a).
Q13. What is the importance of a computational grid in the development of twin screw machines?
Computational fluid dynamics of twin screw machines requires special attention in the generation of a computational grid that needs to represent the highly deforming working chamber in such machines.
Q14. What is the simplest way to constrain the node distribution on the rack curve?
it is possible to constrain the node distribution on the rack segment of the outer boundary to be same for both O blocks of the main and gate rotor and therefore achieve a one to one conformal interface as shown in Figure 14.
Q15. What are the main aspects of the CFD simulations of twin screw machines?
Kovačević et al. (2002, 2005 and 2007) [9, 10, 11] have reported CFD simulations of twin screw machines to predict gas flow, conjugate heat transfer, fluid-structure interaction etc. for variety of screw machines.
Q16. What is the function used to control the position of the node on the outer circle?
Each node on this outer circle is now treated as a controller of the corresponding node to be placed on the inner boundary as shown in Figure 9a.