Frequently Asked Questions
The two codes can be used in many industries and applicable to all types of turbomachinery including Compressible or Incompressible flow, Radial, mixed, and axial-flow machines, Rotational or Stationary and Turbine flow or Pump flow. Further details on the applications of the TURBOdesign family of design codes can be found in the Applications section.
TURBOdesign-1 enables the control of 3D pressure fields through the loading distribution, thereby allowing the user to address flow features such as secondary flows and 3D flow separation in a direct manner. It has lead to breakthrough designs in many Turbomachinery applications, its benefits are as follows:
- Full 3D Inverse method.
- Complete control of 3D pressure fields through blade loading.
- Innovative design beyond previous experience.
- Easy to export the resulting geometry to major CFD, CAD and FEA system.
- Valuable manpower and design time savings.
- Easy to generate database of design know how.
- Logical feedback of CFD results to design inputs.
- Direct portability of design inputs from one design to another.
- TURBOdesign-1 is a full 3D invicid inverse turbomachinery design method. Input the blade loading, meridional geometry, thickness, and stacking axis, and in a matter of minutes you have inversely designed your blade geometry. Designers can drastically cut design times by using their insight into the flow field to design the blade rather than using trial and error. TURBOdesign-1 can be applied to the design of all types of turbomachinery blades, compressible or incompressible, rotating or stationary, axial, mixed flow or radial. TURBOdesign-1 has no shock capturing but can be applied in the transonic flow regime.
- TURBOdesign-2 is a viscous 3D transonic inverse design method. It was developed in particular for the design of high pressure ratio axial transonic fans and compressors where most of the pressure rise near the tip occurs due to the shock. The code models the effect of viscosity and can capture shock waves.
TURBOdesign-1 and TURBOdesign-2 are the main software products offered, ADT also offer Consultancy and Engineering Services.
Unlike the conventional or direct approach where the geometry is changed iteratively by using the application of CFD analysis methods and through trial and error until the optimum flow conditions are obtained. With the Inverse approach the geometry is computed for a specified optimum flow distribution, where the loading distribution is specified and then the blade geometry is computed, this approach is much quicker in generating the blade geometry. The inverse approach has been used previously using 2D methods, with the surface velocity specified, but these methods offered no control over blade thickness and it was difficult to ensure structural integrity and difficult to apply in 3D because of hub to shroud compatibility conditions. Other areas of development in the Inverse method include stating the velocity on one surface and blade thickness, but it is difficult to apply in 3D because of hub to shroud compatibility conditions. Only when the blade loading, blade distribution and blade thickness parameters were entered as an input requirement that the Inverse approach ensured a design that not only satisfied structural considerations, but could be applied in 3D and allowed the possibility to design for a fixed Euler work.
The process of finding the optimum blade loading in many problems can start by considering the results of a CFD computation of an equivalent conventionally designed blade row. By detailed study of the flow field in the blade one can understand the main flow mechanism which generate most of the loss. For example it could be flow separation, secondary flows, shock waves, tip clearance etc. Appropriate choice of blade loading can then help to minimize losses. For example to control tip clearance in centrifugal compressor an aftloaded distribution can be beneficial as it is important to reduce tip clearance in the inducer section of the impeller.. One important aspect of the design is that once the optimum blade loading for a particular type of machine if found the results are quite general and can be applied with ease to machine of similar type.
In the past many types of design specifications have been employed. Many of the early 2D methods used blade surface pressure on both surfaces . However, such an approach has server limitation as the blade thickness can not specified and in many cases it is impossible to ensure the closure of the blade. Alternative approaches to get round this problem has been based on the specification of the blade pressure distribution on one surface, normally the suction surface, and the blade thickness. However, both of these approaches can not be readily applied in 3D as the pressure distribution at each streamline is dependent on the streamline patterns and the distribution of pressure at other streamwise sections. This so called compatability condition means that methods based on specification of surface pressure on either one or two blade surfaces may not always provide a solution for a specified pressure distribution. In TURBOdesign1 and Method 1 of TURBOdesign2, the blade loading or meridional derivative of rVθ is specified together with blade thickness. This provides a number of advantages. Firstly the method can be applied in a robust and consistent manner in 3D. Also the blade loading is directly related to pressure jump across the blade and hence one can have control over the 3D pressure field. In addition the area under the blade loading diagram for each streamwise section is directly related to the specific work and hence once can implicitly ensure that the blade is designed for a given specific work.
The main input parameters are Rotating Speed, Inlet Flow Distribution (which are specified), the Meridional Profile, Blade Number and Blade Thickness (which are assumed based on experience and structural strength) with the most important parameters being the Blade Loading and the Stacking Condition, (which are specified). Any assumed data may be optimised separately once other parameters are optimised.
Existing version of TURBOdesign2 is limited to design of compressible axial machines. The existing version os also limited to the design of a single blade row at a time.
- Inviscid theory.
- Boundary layer growth and separation are not modeled. User needs to check the viscous effects by using CFD analysis.
- Design code for single blade row.
- Thin blade theory : In the case of the thick blade such as axial turbine blades, accurate control of pressure distribution on the blade can prove difficult, but in many success have already been accomplished with the assessment of the CFD code.
- Poor convergence of the 3D version of the code for low specific speed pump applications. However, the Actuator Duct or throughflow version of the code can be used for the design of these types of machines.
- Geometry is optimized from a fluid dynamic point of view : Manufacturing and stress considerations must be taken into account separately and in some cases manufacturing requirements may require a compromise on performance.
The current version of TURBOdesign-1 does not allow users to directly specify geometric constaints. However, there are a number of ways in which the blade geometry can be simplified by the choice of the blade loading specification. ADT has developed considerable know-how in this area which it shares with its customers.
In TURBOdesign1 it is possible to specify the normal thickness which in most cases should help to ensure the structural integrity of the design. However in some cases TURBOdesign1 and TURBOdesign2 can create complicated 3D blade geometries. Care should be taken in the choice of blade loading and stacking conditions in order to minimize bending stresses. ADT has developed considerable amount of know-how in this area which is made available to customers of TURBOdeisgn1 and TURBOdesign2. Also the blade geometry can be easily exported to FEA codes through the IGES and STL file formats for detailed analysis of the stress and vibration characteristic of the designed blade.
Yes, it is. TURBOdesign2 uses 3D Euler solver including viscous effects to solve flow field in the blade passage.
TURBOdesign1 is a design software for turbomachines, and it doesn't have the functionality for the performance prediction and CFD analysis capability. However a Q3D inviscid flow solver will be implemented in TURBOdesign1 in the near future to enable the computation of blade loading on existing blade rows. This code will help to convert conventional design database into one based on the loading distribution. Also in early 2005 ADT will release an accurate and fast 3D CFD code as an optional package to be used with TURBOdesign1 .
TURBOdesign2 essentially has the capability to solve 3D flow field using 3D Euler solver including viscous effects as other CFD codes. Users can analyze the flow field and performance of the existing blade. However, the most important feature of TURBOdesign2 is its 3D inverse design capability to design the blade geometry to realize the specified loading distribution. Existing CFD code can analyze the flow filed in the turbomachinery but never suggest the direction of the blade geometry modification from the results.
TURBOdesign1 is quite different from CFD. TURBOdesign1 is an inverse design software for turbomachines in which the 3D blade geometry will be calculated inversely from the specified loading distribution, and it doesn't have the functionality for the performance prediction and CFD analysis capability. However TURBOdesign1 not only computes the blade geometry but it also provides very accurate predictions of the 3D inviscid pressure field, which compares quite well with the corresponding predictions of the blade surface pressure distribution.
TURBOdesign1 has the functionality to convert the geometry data from inverse design to other CFD, structural analysis or CAD software. The following file conversions are supported:
- Fluent G/Turbo
- CFX BladeGen
- CFX TurboGrid
- Es Turbo (STARCD)
Existing database should be the good start point for the inverse design. User can use existing meridional geometry, thickness distribution and design work requirement from the existing experimental or analysis results. Also the loading distribution of existing designs can be obtained from CFD computations and used as a starting point in the choice of blade loading when using TURBOdesign-1. In the next release of TURBOdesign-1 (version 2.3) planned for Q2 of 2005 a quasi-3D analysis code will be provided which enable users to obtain the loading distribution on any existing blades with ease and then import that into TURBOdesign-1 as a starting point of their redesign process.
- Trial License - For Evaluation of the Code, ADT will provide a license to a customer for a period up to 6 months, thus allowing the customer to fully evaluate and analysis the code.
- Academic License and R&D Institute License -This license is for academic use only and is provided at a highly discounted rate to you on the condition that you agree to the following points, Supply ADT with a copy of any published paper that is produced as a result of using the Software, credit ADT in any paper as the provider of the solver used in the research and do not benefit from fees received from a commercial company or any third party.
- Annual License - non-exclusive, non-transferable license will include Free upgrade service for new versions, user and application manuals, Two days on-site training, Hotline support by phone, fax, email.
- Permanent License - Yearly maintenance fee will include Free upgrade service for new versions, user and application manuals, Two days on-site training, Hotline support by phone, fax, email.
There are several ways to evaluate the codes shown as follows:
- Demonstration Design - An ADT project manager will redesign and help optimize a single blade row using the code. Once the geometry has been generated, the results will be sent back to the customer who can evaluate the results by using CFD or experimentally. This option allows the customer to compare the results to what is currently being achieved. The design, however, can not be commercially exploited until the customer purchases an annual license.
- Trial License - ADT will issue the code to the customer for in-house evaluation. This is for a period of either 3 months or 6 months. Or a time period can be negotiated to suit the customers need. This allows the customer to fully evaluate the code in house.
- Trial License with Demonstration Design - This is the best way of evaluating the code. As it allows the customer to try the code in-house and at the same time it allows for close collaboration and transfer of design know-how from ADT project manager to the customers designers.
Yes, as long as the when the license is installed on the server the file can be accessed by the workstation, the only limitation is that if it is a single seat only one user at a time can use the code.