Flow Path Optimization of Pneumatic Valves Through CFD Analysis

  • N. PrabhakarEmail author
  • G. Gopinath
  • S. Bharathiraja
  • M. Praveen
  • V. R. SwaroopRaj
Conference paper
Part of the Lecture Notes on Multidisciplinary Industrial Engineering book series (LNMUINEN)


Relay emergency valves are typical pneumatic flow control valves which are primarily used in air brake vehicles to speed up the application and release of rear axle(s) brakes. This valve will also have additional provision to apply the trailer brake automatically in the event of accidental decoupling of trailer. The relay emergency valve will graduate, hold, and release of air pressure from the brake chambers to which it is connected. The relay emergency valve is used to reduce the response time of brake applications on heavy-duty vehicles. In order to achieve higher valve response, the valve should yield high flow rate for a wide range of operating pressures. Higher flow output can be achieved with the minimum flow restriction in the valves. To achieve different product functions, the assembly will have subparts like piston, springs, seals, etc. which will restrict the flow passage. To achieve high flow rate without sacrificing the product function, the valve flow area should be maximum. Hence, computational fluid dynamics (CFD) can be utilized as a useful design tool to optimize the flow area of relay emergency valves and also to study the effect of flow restrictions. This paper covers the optimization of the flow path by finding the nominal flow diameters as per ISO 6358. A thorough CFD analysis with several design iterations of the valve has been made to improve and finalize the nominal flow diameter with the required flow rate at the outlet to meet the design requirements. The theoretical results are in good agreement with the experiments.


Nominal flow diameter Pneumatic valves Relay emergency valves 


  1. 1.
    Prabhakar, N., Sripathy, P., Bharathiraja, S., Ayyappan, K.: Theoretical and Experimental Investigation of Flow Rate of Leveling Valve with Filters for Different Operating Angles. SAE Technical Paper 2013-26-0042 (2013)Google Scholar
  2. 2.
    Moujaes, S.F., Jagan, R.: 3D CFD Predictions and Experimental Comparisons of Pressure Drop in a Ball Valve at Different Partial Openings in Turbulent Flow. J. Energy Eng. (ASCE_0733-9402) (2008)Google Scholar
  3. 3.
    ISO 6358 Pneumatic Determination of Flow Rate Characteristics of Components Using Compressible FluidsGoogle Scholar
  4. 4.
    DIN1343 Normal and Standard ConditionsGoogle Scholar
  5. 5.
    Beater, P.: Pneumatic drives- system, modeling and control. In: White, F.M. (Eds.) Fluid Mechanics. McGraw Hill, New York, USA (1986)Google Scholar

Copyright information

© Springer Nature Singapore Pte Ltd. 2020

Authors and Affiliations

  1. 1.WABCO India LimitedChennaiIndia

Personalised recommendations